This article is a summary of differentiation rules , that is, rules for computing the derivative  of a function  in calculus .
Elementary rules of differentiation 
Unless otherwise stated, all functions are functions of real numbers  (
  
    
      
        
          R 
         
       
     
    {\textstyle \mathbb {R} } 
   
 well defined ,[ 1] [ 2] complex numbers  (
  
    
      
        
          C 
         
       
     
    {\textstyle \mathbb {C} } 
   
 [ 3] 
Constant term rule 
For any value of 
  
    
      
        c 
       
     
    {\textstyle c} 
   
 
  
    
      
        c 
        ∈ 
        
          R 
         
       
     
    {\textstyle c\in \mathbb {R} } 
   
 
  
    
      
        f 
        ( 
        x 
        ) 
       
     
    {\textstyle f(x)} 
   
 
  
    
      
        f 
        ( 
        x 
        ) 
        = 
        c 
       
     
    {\textstyle f(x)=c} 
   
 
  
    
      
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        = 
        0 
       
     
    {\textstyle {\frac {df}{dx}}=0} 
   
 [ 4] 
Proof 
Let 
  
    
      
        c 
        ∈ 
        
          R 
         
       
     
    {\textstyle c\in \mathbb {R} } 
   
 
  
    
      
        f 
        ( 
        x 
        ) 
        = 
        c 
       
     
    {\textstyle f(x)=c} 
   
 
  
    
      
        
          
            
              
                
                  f 
                  ′ 
                 
                ( 
                x 
                ) 
               
              
                = 
                
                  lim 
                  
                    h 
                    → 
                    0 
                   
                 
                
                  
                    
                      f 
                      ( 
                      x 
                      + 
                      h 
                      ) 
                      − 
                      f 
                      ( 
                      x 
                      ) 
                     
                    h 
                   
                 
               
             
            
              
                = 
                
                  lim 
                  
                    h 
                    → 
                    0 
                   
                 
                
                  
                    
                      ( 
                      c 
                      ) 
                      − 
                      ( 
                      c 
                      ) 
                     
                    h 
                   
                 
               
             
            
              
                = 
                
                  lim 
                  
                    h 
                    → 
                    0 
                   
                 
                
                  
                    0 
                    h 
                   
                 
               
             
            
              
                = 
                
                  lim 
                  
                    h 
                    → 
                    0 
                   
                 
                0 
               
             
            
              
                = 
                0. 
               
             
           
         
       
     
    {\displaystyle {\begin{aligned}f'(x)&=\lim _{h\to 0}{\frac {f(x+h)-f(x)}{h}}\\&=\lim _{h\to 0}{\frac {(c)-(c)}{h}}\\&=\lim _{h\to 0}{\frac {0}{h}}\\&=\lim _{h\to 0}0\\&=0.\end{aligned}}} 
   
 
This computation shows that the derivative of any constant function is 0. 
The derivative  of the function at a point is the slope of the line tangent  to the curve at the point. The slope  of the constant function is 0, because the tangent line  to the constant function is horizontal and its angle is 0.
In other words, the value of the constant function, 
  
    
      
        y 
       
     
    {\textstyle y} 
   
 
  
    
      
        x 
       
     
    {\textstyle x} 
   
 
At each point, the derivative  is the slope of a line  that is tangent  to the curve  at that point. Note: the derivative at point A is positive  where green and dash–dot, negative  where red and dashed, and 0  where black and solid. 
Differentiation is linear 
For any functions 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        a 
       
     
    {\textstyle a} 
   
 
  
    
      
        b 
       
     
    {\textstyle b} 
   
 
  
    
      
        h 
        ( 
        x 
        ) 
        = 
        a 
        f 
        ( 
        x 
        ) 
        + 
        b 
        g 
        ( 
        x 
        ) 
       
     
    {\textstyle h(x)=af(x)+bg(x)} 
   
 
  
    
      
        x 
       
     
    {\textstyle x} 
   
 
  
    
      
        
          h 
          ′ 
         
        ( 
        x 
        ) 
        = 
        a 
        
          f 
          ′ 
         
        ( 
        x 
        ) 
        + 
        b 
        
          g 
          ′ 
         
        ( 
        x 
        ) 
       
     
    {\textstyle h'(x)=af'(x)+bg'(x)} 
   
 
In Leibniz's notation , this formula is written as:
  
    
      
        
          
            
              d 
              ( 
              a 
              f 
              + 
              b 
              g 
              ) 
             
            
              d 
              x 
             
           
         
        = 
        a 
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        + 
        b 
        
          
            
              d 
              g 
             
            
              d 
              x 
             
           
         
        . 
       
     
    {\displaystyle {\frac {d(af+bg)}{dx}}=a{\frac {df}{dx}}+b{\frac {dg}{dx}}.} 
   
 
Special cases include:
The constant factor rule: 
  
    
      
        ( 
        a 
        f 
        
          ) 
          ′ 
         
        = 
        a 
        
          f 
          ′ 
         
        , 
       
     
    {\displaystyle (af)'=af',} 
   
 
  
    
      
        ( 
        f 
        + 
        g 
        
          ) 
          ′ 
         
        = 
        
          f 
          ′ 
         
        + 
        
          g 
          ′ 
         
        , 
       
     
    {\displaystyle (f+g)'=f'+g',} 
   
 
  
    
      
        ( 
        f 
        − 
        g 
        
          ) 
          ′ 
         
        = 
        
          f 
          ′ 
         
        − 
        
          g 
          ′ 
         
        . 
       
     
    {\displaystyle (f-g)'=f'-g'.} 
   
 
Product rule 
For the functions 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        h 
        ( 
        x 
        ) 
        = 
        f 
        ( 
        x 
        ) 
        g 
        ( 
        x 
        ) 
       
     
    {\textstyle h(x)=f(x)g(x)} 
   
 
  
    
      
        x 
       
     
    {\textstyle x} 
   
 
  
    
      
        
          h 
          ′ 
         
        ( 
        x 
        ) 
        = 
        ( 
        f 
        g 
        
          ) 
          ′ 
         
        ( 
        x 
        ) 
        = 
        
          f 
          ′ 
         
        ( 
        x 
        ) 
        g 
        ( 
        x 
        ) 
        + 
        f 
        ( 
        x 
        ) 
        
          g 
          ′ 
         
        ( 
        x 
        ) 
        . 
       
     
    {\displaystyle h'(x)=(fg)'(x)=f'(x)g(x)+f(x)g'(x).} 
   
 
In Leibniz's notation, this formula is written:
  
    
      
        
          
            
              d 
              ( 
              f 
              g 
              ) 
             
            
              d 
              x 
             
           
         
        = 
        g 
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        + 
        f 
        
          
            
              d 
              g 
             
            
              d 
              x 
             
           
         
        . 
       
     
    {\displaystyle {\frac {d(fg)}{dx}}=g{\frac {df}{dx}}+f{\frac {dg}{dx}}.} 
   
 
Chain rule 
The derivative of the function 
  
    
      
        h 
        ( 
        x 
        ) 
        = 
        f 
        ( 
        g 
        ( 
        x 
        ) 
        ) 
       
     
    {\textstyle h(x)=f(g(x))} 
   
 
  
    
      
        
          h 
          ′ 
         
        ( 
        x 
        ) 
        = 
        
          f 
          ′ 
         
        ( 
        g 
        ( 
        x 
        ) 
        ) 
        ⋅ 
        
          g 
          ′ 
         
        ( 
        x 
        ) 
        . 
       
     
    {\displaystyle h'(x)=f'(g(x))\cdot g'(x).} 
   
 
In Leibniz's notation, this formula is written as:
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        h 
        ( 
        x 
        ) 
        = 
        
          
            
              
                
                  d 
                  
                    d 
                    z 
                   
                 
               
              f 
              ( 
              z 
              ) 
             
            | 
           
          
            z 
            = 
            g 
            ( 
            x 
            ) 
           
         
        ⋅ 
        
          
            d 
            
              d 
              x 
             
           
         
        g 
        ( 
        x 
        ) 
        , 
       
     
    {\displaystyle {\frac {d}{dx}}h(x)=\left.{\frac {d}{dz}}f(z)\right|_{z=g(x)}\cdot {\frac {d}{dx}}g(x),} 
   
 
  
    
      
        
          
            
              d 
              h 
              ( 
              x 
              ) 
             
            
              d 
              x 
             
           
         
        = 
        
          
            
              d 
              f 
              ( 
              g 
              ( 
              x 
              ) 
              ) 
             
            
              d 
              g 
              ( 
              x 
              ) 
             
           
         
        ⋅ 
        
          
            
              d 
              g 
              ( 
              x 
              ) 
             
            
              d 
              x 
             
           
         
        . 
       
     
    {\displaystyle {\frac {dh(x)}{dx}}={\frac {df(g(x))}{dg(x)}}\cdot {\frac {dg(x)}{dx}}.} 
   
 
Focusing on the notion of maps, and the differential being a map 
  
    
      
        
          D 
         
       
     
    {\textstyle {\text{D}}} 
   
 
  
    
      
        [ 
        
          D 
         
        ( 
        f 
        ∘ 
        g 
        ) 
        
          ] 
          
            x 
           
         
        = 
        [ 
        
          D 
         
        f 
        
          ] 
          
            g 
            ( 
            x 
            ) 
           
         
        ⋅ 
        [ 
        
          D 
         
        g 
        
          ] 
          
            x 
           
         
        . 
       
     
    {\displaystyle [{\text{D}}(f\circ g)]_{x}=[{\text{D}}f]_{g(x)}\cdot [{\text{D}}g]_{x}.} 
   
 
Inverse function rule 
If the function 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 inverse function  
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        g 
        ( 
        f 
        ( 
        x 
        ) 
        ) 
        = 
        x 
       
     
    {\textstyle g(f(x))=x} 
   
 
  
    
      
        f 
        ( 
        g 
        ( 
        y 
        ) 
        ) 
        = 
        y 
       
     
    {\textstyle f(g(y))=y} 
   
 
  
    
      
        
          g 
          ′ 
         
        = 
        
          
            1 
            
              
                f 
                ′ 
               
              ∘ 
              g 
             
           
         
        . 
       
     
    {\displaystyle g'={\frac {1}{f'\circ g}}.} 
   
 
In Leibniz notation, this formula is written as:
  
    
      
        
          
            
              d 
              x 
             
            
              d 
              y 
             
           
         
        = 
        
          
            1 
            
              
                d 
                y 
               
              
                d 
                x 
               
             
           
         
        . 
       
     
    {\displaystyle {\frac {dx}{dy}}={\frac {1}{\frac {dy}{dx}}}.} 
   
 
Polynomial or elementary power rule 
If 
  
    
      
        f 
        ( 
        x 
        ) 
        = 
        
          x 
          
            r 
           
         
       
     
    {\textstyle f(x)=x^{r}} 
   
 
  
    
      
        r 
        ≠ 
        0 
       
     
    {\textstyle r\neq 0} 
   
 
  
    
      
        
          f 
          ′ 
         
        ( 
        x 
        ) 
        = 
        r 
        
          x 
          
            r 
            − 
            1 
           
         
        . 
       
     
    {\displaystyle f'(x)=rx^{r-1}.} 
   
 
When 
  
    
      
        r 
        = 
        1 
       
     
    {\textstyle r=1} 
   
 
  
    
      
        f 
        ( 
        x 
        ) 
        = 
        x 
       
     
    {\textstyle f(x)=x} 
   
 
  
    
      
        
          f 
          ′ 
         
        ( 
        x 
        ) 
        = 
        1 
       
     
    {\textstyle f'(x)=1} 
   
 
Combining the power rule with the sum and constant multiple rules permits the computation of the derivative of any polynomial.
Reciprocal rule 
The derivative of 
  
    
      
        h 
        ( 
        x 
        ) 
        = 
        
          
            1 
            
              f 
              ( 
              x 
              ) 
             
           
         
       
     
    {\textstyle h(x)={\frac {1}{f(x)}}} 
   
 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        
          h 
          ′ 
         
        ( 
        x 
        ) 
        = 
        − 
        
          
            
              
                f 
                ′ 
               
              ( 
              x 
              ) 
             
            
              ( 
              f 
              ( 
              x 
              ) 
              
                ) 
                
                  2 
                 
               
             
           
         
        , 
       
     
    {\displaystyle h'(x)=-{\frac {f'(x)}{(f(x))^{2}}},} 
   
 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
In Leibniz's notation, this formula is written:
  
    
      
        
          
            
              d 
              
                ( 
                
                  
                    1 
                    f 
                   
                 
                ) 
               
             
            
              d 
              x 
             
           
         
        = 
        − 
        
          
            1 
            
              f 
              
                2 
               
             
           
         
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        . 
       
     
    {\displaystyle {\frac {d\left({\frac {1}{f}}\right)}{dx}}=-{\frac {1}{f^{2}}}{\frac {df}{dx}}.} 
   
 
The reciprocal rule can be derived either from the quotient rule or from the combination of power rule and chain rule.
Quotient rule 
If 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        
          
            ( 
            
              
                f 
                g 
               
             
            ) 
           
          ′ 
         
        = 
        
          
            
              
                f 
                ′ 
               
              g 
              − 
              
                g 
                ′ 
               
              f 
             
            
              g 
              
                2 
               
             
           
         
        , 
       
     
    {\displaystyle \left({\frac {f}{g}}\right)'={\frac {f'g-g'f}{g^{2}}},} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
This can be derived from the product rule and the reciprocal rule.
Generalized power rule 
The elementary power rule generalizes considerably. The most general power rule is the functional power rule : for any functions 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        ( 
        
          f 
          
            g 
           
         
        
          ) 
          ′ 
         
        = 
        
          
            ( 
            
              e 
              
                g 
                ln 
                 
                f 
               
             
            ) 
           
          ′ 
         
        = 
        
          f 
          
            g 
           
         
        
          ( 
          
            
              f 
              ′ 
             
            
              
                g 
                f 
               
             
            + 
            
              g 
              ′ 
             
            ln 
             
            f 
           
          ) 
         
        , 
         
     
    {\displaystyle (f^{g})'=\left(e^{g\ln f}\right)'=f^{g}\left(f'{g \over f}+g'\ln f\right),\quad } 
   
 
Special cases:
If 
  
    
      
        f 
        ( 
        x 
        ) 
        = 
        
          x 
          
            a 
           
         
       
     
    {\textstyle f(x)=x^{a}} 
   
 
  
    
      
        
          f 
          ′ 
         
        ( 
        x 
        ) 
        = 
        a 
        
          x 
          
            a 
            − 
            1 
           
         
       
     
    {\textstyle f'(x)=ax^{a-1}} 
   
 
  
    
      
        a 
       
     
    {\textstyle a} 
   
 
  
    
      
        x 
       
     
    {\textstyle x} 
   
  
The reciprocal rule may be derived as the special case where 
  
    
      
        g 
        ( 
        x 
        ) 
        = 
        − 
        1 
         
     
    {\textstyle g(x)=-1\!} 
   
  
Derivatives of exponential and logarithmic functions 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            c 
            
              a 
              x 
             
           
          ) 
         
        = 
        
          a 
          
            c 
            
              a 
              x 
             
           
          ln 
           
          c 
         
        , 
        c 
        > 
        0. 
       
     
    {\displaystyle {\frac {d}{dx}}\left(c^{ax}\right)={ac^{ax}\ln c},\qquad c>0.} 
   
 
  
    
      
        c 
       
     
    {\displaystyle c} 
   
 
  
    
      
        c 
        < 
        0 
       
     
    {\displaystyle c<0} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            e 
            
              a 
              x 
             
           
          ) 
         
        = 
        a 
        
          e 
          
            a 
            x 
           
         
        . 
       
     
    {\displaystyle {\frac {d}{dx}}\left(e^{ax}\right)=ae^{ax}.} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            
              log 
              
                c 
               
             
             
            x 
           
          ) 
         
        = 
        
          
            1 
            
              x 
              ln 
               
              c 
             
           
         
        , 
        c 
        > 
        1. 
       
     
    {\displaystyle {\frac {d}{dx}}\left(\log _{c}x\right)={1 \over x\ln c},\qquad c>1.} 
   
 
  
    
      
        c 
       
     
    {\textstyle c} 
   
 
  
    
      
        c 
        < 
        0 
       
     
    {\textstyle c<0} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            ln 
             
            x 
           
          ) 
         
        = 
        
          
            1 
            x 
           
         
        , 
        x 
        > 
        0. 
       
     
    {\displaystyle {\frac {d}{dx}}\left(\ln x\right)={1 \over x},\qquad x>0.} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            ln 
             
            
              | 
             
            x 
            
              | 
             
           
          ) 
         
        = 
        
          
            1 
            x 
           
         
        , 
        x 
        ≠ 
        0. 
       
     
    {\displaystyle {\frac {d}{dx}}\left(\ln |x|\right)={1 \over x},\qquad x\neq 0.} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            W 
            ( 
            x 
            ) 
           
          ) 
         
        = 
        
          
            1 
            
              x 
              + 
              
                e 
                
                  W 
                  ( 
                  x 
                  ) 
                 
               
             
           
         
        , 
        x 
        > 
        − 
        
          
            1 
            e 
           
         
        , 
       
     
    {\displaystyle {\frac {d}{dx}}\left(W(x)\right)={1 \over {x+e^{W(x)}}},\qquad x>-{1 \over e},} 
   
 
  
    
      
        W 
        ( 
        x 
        ) 
       
     
    {\textstyle W(x)} 
   
 Lambert W function .
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            x 
            
              x 
             
           
          ) 
         
        = 
        
          x 
          
            x 
           
         
        ( 
        1 
        + 
        ln 
         
        x 
        ) 
        . 
       
     
    {\displaystyle {\frac {d}{dx}}\left(x^{x}\right)=x^{x}(1+\ln x).} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            f 
            ( 
            x 
            
              ) 
              
                g 
                ( 
                x 
                ) 
               
             
           
          ) 
         
        = 
        g 
        ( 
        x 
        ) 
        f 
        ( 
        x 
        
          ) 
          
            g 
            ( 
            x 
            ) 
            − 
            1 
           
         
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        + 
        f 
        ( 
        x 
        
          ) 
          
            g 
            ( 
            x 
            ) 
           
         
        ln 
         
        
          ( 
          f 
          ( 
          x 
          ) 
          ) 
         
        
          
            
              d 
              g 
             
            
              d 
              x 
             
           
         
        , 
        
          if  
         
        f 
        ( 
        x 
        ) 
        > 
        0 
        
           and  
         
        
          
            
              d 
              f 
             
            
              d 
              x 
             
           
         
        
           and  
         
        
          
            
              d 
              g 
             
            
              d 
              x 
             
           
         
        
           exist. 
         
       
     
    {\displaystyle {\frac {d}{dx}}\left(f(x)^{g(x)}\right)=g(x)f(x)^{g(x)-1}{\frac {df}{dx}}+f(x)^{g(x)}\ln {(f(x))}{\frac {dg}{dx}},\qquad {\text{if }}f(x)>0{\text{ and }}{\frac {df}{dx}}{\text{ and }}{\frac {dg}{dx}}{\text{ exist.}}} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        
          ( 
          
            
              f 
              
                1 
               
             
            ( 
            x 
            
              ) 
              
                
                  f 
                  
                    2 
                   
                 
                ( 
                x 
                
                  ) 
                  
                    
                      
                        ( 
                        
                          . 
                          . 
                          . 
                         
                        ) 
                       
                      
                        
                          f 
                          
                            n 
                           
                         
                        ( 
                        x 
                        ) 
                       
                     
                   
                 
               
             
           
          ) 
         
        = 
        
          [ 
          
            
              ∑ 
              
                k 
                = 
                1 
               
              
                n 
               
             
            
              
                ∂ 
                
                  ∂ 
                  
                    x 
                    
                      k 
                     
                   
                 
               
             
            
              ( 
              
                
                  f 
                  
                    1 
                   
                 
                ( 
                
                  x 
                  
                    1 
                   
                 
                
                  ) 
                  
                    
                      f 
                      
                        2 
                       
                     
                    ( 
                    
                      x 
                      
                        2 
                       
                     
                    
                      ) 
                      
                        
                          
                            ( 
                            
                              . 
                              . 
                              . 
                             
                            ) 
                           
                          
                            
                              f 
                              
                                n 
                               
                             
                            ( 
                            
                              x 
                              
                                n 
                               
                             
                            ) 
                           
                         
                       
                     
                   
                 
               
              ) 
             
           
          ] 
         
        
          
            
              | 
             
           
          
            
              x 
              
                1 
               
             
            = 
            
              x 
              
                2 
               
             
            = 
            . 
            . 
            . 
            = 
            
              x 
              
                n 
               
             
            = 
            x 
           
         
        , 
        
           if  
         
        
          f 
          
            i 
            < 
            n 
           
         
        ( 
        x 
        ) 
        > 
        0 
        
           and  
         
        
          
            
              d 
              
                f 
                
                  i 
                 
               
             
            
              d 
              x 
             
           
         
        
           exists. 
         
       
     
    {\displaystyle {\frac {d}{dx}}\left(f_{1}(x)^{f_{2}(x)^{\left(...\right)^{f_{n}(x)}}}\right)=\left[\sum \limits _{k=1}^{n}{\frac {\partial }{\partial x_{k}}}\left(f_{1}(x_{1})^{f_{2}(x_{2})^{\left(...\right)^{f_{n}(x_{n})}}}\right)\right]{\biggr \vert }_{x_{1}=x_{2}=...=x_{n}=x},\qquad {\text{ if }}f_{i<n}(x)>0{\text{ and }}{\frac {df_{i}}{dx}}{\text{ exists.}}} 
   
 
Logarithmic derivatives 
The logarithmic derivative  is another way of stating the rule for differentiating the logarithm  of a function (using the chain rule):
  
    
      
        ( 
        ln 
         
        f 
        
          ) 
          ′ 
         
        = 
        
          
            
              f 
              ′ 
             
            f 
           
         
        , 
       
     
    {\displaystyle (\ln f)'={\frac {f'}{f}},} 
   
 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
Logarithmic differentiation  is a technique which uses logarithms and its differentiation rules to simplify certain expressions before actually applying the derivative.
Logarithms can be used to remove exponents, convert products into sums, and convert division into subtraction—each of which may lead to a simplified expression for taking derivatives.
Derivatives of trigonometric functions 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        sin 
         
        x 
        = 
        cos 
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\sin x=\cos x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arcsin 
         
        x 
        = 
        
          
            1 
            
              1 
              − 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\arcsin x={\frac {1}{\sqrt {1-x^{2}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        cos 
         
        x 
        = 
        − 
        sin 
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\cos x=-\sin x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arccos 
         
        x 
        = 
        − 
        
          
            1 
            
              1 
              − 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\arccos x=-{\frac {1}{\sqrt {1-x^{2}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        tan 
         
        x 
        = 
        
          sec 
          
            2 
           
         
         
        x 
        = 
        
          
            1 
            
              
                cos 
                
                  2 
                 
               
               
              x 
             
           
         
        = 
        1 
        + 
        
          tan 
          
            2 
           
         
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\tan x=\sec ^{2}x={\frac {1}{\cos ^{2}x}}=1+\tan ^{2}x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arctan 
         
        x 
        = 
        
          
            1 
            
              1 
              + 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\arctan x={\frac {1}{1+x^{2}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        csc 
         
        x 
        = 
        − 
        csc 
         
        
          x 
         
        cot 
         
        
          x 
         
       
     
    {\displaystyle {\frac {d}{dx}}\csc x=-\csc {x}\cot {x}} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arccsc 
         
        x 
        = 
        − 
        
          
            1 
            
              
                | 
               
              x 
              
                | 
               
              
                
                  
                    x 
                    
                      2 
                     
                   
                  − 
                  1 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arccsc} x=-{\frac {1}{|x|{\sqrt {x^{2}-1}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        sec 
         
        x 
        = 
        sec 
         
        
          x 
         
        tan 
         
        
          x 
         
       
     
    {\displaystyle {\frac {d}{dx}}\sec x=\sec {x}\tan {x}} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arcsec 
         
        x 
        = 
        
          
            1 
            
              
                | 
               
              x 
              
                | 
               
              
                
                  
                    x 
                    
                      2 
                     
                   
                  − 
                  1 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arcsec} x={\frac {1}{|x|{\sqrt {x^{2}-1}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        cot 
         
        x 
        = 
        − 
        
          csc 
          
            2 
           
         
         
        x 
        = 
        − 
        
          
            1 
            
              
                sin 
                
                  2 
                 
               
               
              x 
             
           
         
        = 
        − 
        1 
        − 
        
          cot 
          
            2 
           
         
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\cot x=-\csc ^{2}x=-{\frac {1}{\sin ^{2}x}}=-1-\cot ^{2}x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arccot 
         
        x 
        = 
        − 
        
          
            1 
            
              1 
              + 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arccot} x=-{1 \over 1+x^{2}}} 
   
  
The derivatives in the table above are for when the range of the inverse secant is 
  
    
      
        [ 
        0 
        , 
        π 
        ] 
       
     
    {\textstyle [0,\pi ]} 
   
 
  
    
      
        
          [ 
          
            − 
            
              
                π 
                2 
               
             
            , 
            
              
                π 
                2 
               
             
           
          ] 
         
       
     
    {\textstyle \left[-{\frac {\pi }{2}},{\frac {\pi }{2}}\right]} 
   
 
It is common to additionally define an inverse tangent function with two arguments , 
  
    
      
        arctan 
         
        ( 
        y 
        , 
        x 
        ) 
       
     
    {\textstyle \arctan(y,x)} 
   
 
  
    
      
        [ 
        − 
        π 
        , 
        π 
        ] 
       
     
    {\textstyle [-\pi ,\pi ]} 
   
 
  
    
      
        ( 
        x 
        , 
        y 
        ) 
       
     
    {\textstyle (x,y)} 
   
 
  
    
      
        x 
        > 
        0 
       
     
    {\displaystyle x>0} 
   
 
  
    
      
        arctan 
         
        ( 
        y 
        , 
        x 
        > 
        0 
        ) 
        = 
        arctan 
         
        ( 
        
          
            y 
            x 
           
         
        ) 
       
     
    {\textstyle \arctan(y,x>0)=\arctan({\frac {y}{x}})} 
   
 
  
    
      
        
          
            
              ∂ 
              arctan 
               
              ( 
              y 
              , 
              x 
              ) 
             
            
              ∂ 
              y 
             
           
         
        = 
        
          
            x 
            
              
                x 
                
                  2 
                 
               
              + 
              
                y 
                
                  2 
                 
               
             
           
         
        
          and 
         
        
          
            
              ∂ 
              arctan 
               
              ( 
              y 
              , 
              x 
              ) 
             
            
              ∂ 
              x 
             
           
         
        = 
        
          
            
              − 
              y 
             
            
              
                x 
                
                  2 
                 
               
              + 
              
                y 
                
                  2 
                 
               
             
           
         
        . 
       
     
    {\displaystyle {\frac {\partial \arctan(y,x)}{\partial y}}={\frac {x}{x^{2}+y^{2}}}\qquad {\text{and}}\qquad {\frac {\partial \arctan(y,x)}{\partial x}}={\frac {-y}{x^{2}+y^{2}}}.} 
   
 
Derivatives of hyperbolic functions 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        sinh 
         
        x 
        = 
        cosh 
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\sinh x=\cosh x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arsinh 
         
        x 
        = 
        
          
            1 
            
              1 
              + 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arsinh} x={\frac {1}{\sqrt {1+x^{2}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        cosh 
         
        x 
        = 
        sinh 
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\cosh x=\sinh x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arcosh 
         
        x 
        = 
        
          
            1 
            
              
                x 
                
                  2 
                 
               
              − 
              1 
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arcosh} x={\frac {1}{\sqrt {x^{2}-1}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        tanh 
         
        x 
        = 
        
          
            sech 
            
              2 
             
           
           
          x 
         
        = 
        1 
        − 
        
          tanh 
          
            2 
           
         
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\tanh x={\operatorname {sech} ^{2}x}=1-\tanh ^{2}x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        artanh 
         
        x 
        = 
        
          
            1 
            
              1 
              − 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {artanh} x={\frac {1}{1-x^{2}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        csch 
         
        x 
        = 
        − 
        csch 
         
        
          x 
         
        coth 
         
        
          x 
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {csch} x=-\operatorname {csch} {x}\coth {x}} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arcsch 
         
        x 
        = 
        − 
        
          
            1 
            
              
                | 
               
              x 
              
                | 
               
              
                
                  1 
                  + 
                  
                    x 
                    
                      2 
                     
                   
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arcsch} x=-{\frac {1}{|x|{\sqrt {1+x^{2}}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        sech 
         
        x 
        = 
        − 
        sech 
         
        
          x 
         
        tanh 
         
        
          x 
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {sech} x=-\operatorname {sech} {x}\tanh {x}} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arsech 
         
        x 
        = 
        − 
        
          
            1 
            
              x 
              
                
                  1 
                  − 
                  
                    x 
                    
                      2 
                     
                   
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arsech} x=-{\frac {1}{x{\sqrt {1-x^{2}}}}}} 
   
  
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        coth 
         
        x 
        = 
        − 
        
          csch 
          
            2 
           
         
         
        x 
        = 
        1 
        − 
        
          coth 
          
            2 
           
         
         
        x 
       
     
    {\displaystyle {\frac {d}{dx}}\coth x=-\operatorname {csch} ^{2}x=1-\coth ^{2}x} 
   
 
  
    
      
        
          
            d 
            
              d 
              x 
             
           
         
        arcoth 
         
        x 
        = 
        
          
            1 
            
              1 
              − 
              
                x 
                
                  2 
                 
               
             
           
         
       
     
    {\displaystyle {\frac {d}{dx}}\operatorname {arcoth} x={\frac {1}{1-x^{2}}}} 
   
  
Derivatives of special functions 
Gamma function 
  
    
      
        Γ 
        ( 
        x 
        ) 
        = 
        
          ∫ 
          
            0 
           
          
            ∞ 
           
         
        
          t 
          
            x 
            − 
            1 
           
         
        
          e 
          
            − 
            t 
           
         
        d 
        t 
       
     
    {\displaystyle \Gamma (x)=\int _{0}^{\infty }t^{x-1}e^{-t}\,dt} 
   
 
  
    
      
        
          
            
              
                
                  Γ 
                  ′ 
                 
                ( 
                x 
                ) 
               
              
                = 
                
                  ∫ 
                  
                    0 
                   
                  
                    ∞ 
                   
                 
                
                  t 
                  
                    x 
                    − 
                    1 
                   
                 
                
                  e 
                  
                    − 
                    t 
                   
                 
                ln 
                 
                t 
                d 
                t 
               
             
            
              
                = 
                Γ 
                ( 
                x 
                ) 
                
                  ( 
                  
                    
                      ∑ 
                      
                        n 
                        = 
                        1 
                       
                      
                        ∞ 
                       
                     
                    
                      ( 
                      
                        ln 
                         
                        
                          ( 
                          
                            1 
                            + 
                            
                              
                                
                                  1 
                                  n 
                                 
                               
                             
                           
                          ) 
                         
                        − 
                        
                          
                            
                              1 
                              
                                x 
                                + 
                                n 
                               
                             
                           
                         
                       
                      ) 
                     
                    − 
                    
                      
                        
                          1 
                          x 
                         
                       
                     
                   
                  ) 
                 
               
             
            
              
                = 
                Γ 
                ( 
                x 
                ) 
                ψ 
                ( 
                x 
                ) 
                , 
               
             
           
         
       
     
    {\displaystyle {\begin{aligned}\Gamma '(x)&=\int _{0}^{\infty }t^{x-1}e^{-t}\ln t\,dt\\&=\Gamma (x)\left(\sum _{n=1}^{\infty }\left(\ln \left(1+{\dfrac {1}{n}}\right)-{\dfrac {1}{x+n}}\right)-{\dfrac {1}{x}}\right)\\&=\Gamma (x)\psi (x),\end{aligned}}} 
   
 
  
    
      
        ψ 
        ( 
        x 
        ) 
       
     
    {\textstyle \psi (x)} 
   
 digamma function , expressed by the parenthesized expression to the right of 
  
    
      
        Γ 
        ( 
        x 
        ) 
       
     
    {\textstyle \Gamma (x)} 
   
 
Riemann zeta function 
  
    
      
        ζ 
        ( 
        x 
        ) 
        = 
        
          ∑ 
          
            n 
            = 
            1 
           
          
            ∞ 
           
         
        
          
            1 
            
              n 
              
                x 
               
             
           
         
       
     
    {\displaystyle \zeta (x)=\sum _{n=1}^{\infty }{\frac {1}{n^{x}}}} 
   
 
  
    
      
        
          
            
              
                
                  ζ 
                  ′ 
                 
                ( 
                x 
                ) 
               
              
                = 
                − 
                
                  ∑ 
                  
                    n 
                    = 
                    1 
                   
                  
                    ∞ 
                   
                 
                
                  
                    
                      ln 
                       
                      n 
                     
                    
                      n 
                      
                        x 
                       
                     
                   
                 
                = 
                − 
                
                  
                    
                      ln 
                       
                      2 
                     
                    
                      2 
                      
                        x 
                       
                     
                   
                 
                − 
                
                  
                    
                      ln 
                       
                      3 
                     
                    
                      3 
                      
                        x 
                       
                     
                   
                 
                − 
                
                  
                    
                      ln 
                       
                      4 
                     
                    
                      4 
                      
                        x 
                       
                     
                   
                 
                − 
                ⋯ 
               
             
            
              
                = 
                − 
                
                  ∑ 
                  
                    p 
                    
                       prime 
                     
                   
                 
                
                  
                    
                      
                        p 
                        
                          − 
                          x 
                         
                       
                      ln 
                       
                      p 
                     
                    
                      ( 
                      1 
                      − 
                      
                        p 
                        
                          − 
                          x 
                         
                       
                      
                        ) 
                        
                          2 
                         
                       
                     
                   
                 
                
                  ∏ 
                  
                    q 
                    
                       prime 
                     
                    , 
                    q 
                    ≠ 
                    p 
                   
                 
                
                  
                    1 
                    
                      1 
                      − 
                      
                        q 
                        
                          − 
                          x 
                         
                       
                     
                   
                 
               
             
           
         
       
     
    {\displaystyle {\begin{aligned}\zeta '(x)&=-\sum _{n=1}^{\infty }{\frac {\ln n}{n^{x}}}=-{\frac {\ln 2}{2^{x}}}-{\frac {\ln 3}{3^{x}}}-{\frac {\ln 4}{4^{x}}}-\cdots \\&=-\sum _{p{\text{ prime}}}{\frac {p^{-x}\ln p}{(1-p^{-x})^{2}}}\prod _{q{\text{ prime}},q\neq p}{\frac {1}{1-q^{-x}}}\end{aligned}}} 
   
 
Derivatives of integrals 
Suppose that it is required to differentiate with respect to 
  
    
      
        x 
       
     
    {\textstyle x} 
   
 
  
    
      
        F 
        ( 
        x 
        ) 
        = 
        
          ∫ 
          
            a 
            ( 
            x 
            ) 
           
          
            b 
            ( 
            x 
            ) 
           
         
        f 
        ( 
        x 
        , 
        t 
        ) 
        d 
        t 
        , 
       
     
    {\displaystyle F(x)=\int _{a(x)}^{b(x)}f(x,t)\,dt,} 
   
 
where the functions 
  
    
      
        f 
        ( 
        x 
        , 
        t 
        ) 
       
     
    {\textstyle f(x,t)} 
   
 
  
    
      
        
          
            ∂ 
            
              ∂ 
              x 
             
           
         
        f 
        ( 
        x 
        , 
        t 
        ) 
       
     
    {\textstyle {\frac {\partial }{\partial x}}\,f(x,t)} 
   
 
  
    
      
        t 
       
     
    {\textstyle t} 
   
 
  
    
      
        x 
       
     
    {\textstyle x} 
   
 
  
    
      
        ( 
        t 
        , 
        x 
        ) 
       
     
    {\textstyle (t,x)} 
   
 
  
    
      
        a 
        ( 
        x 
        ) 
        ≤ 
        t 
        ≤ 
        b 
        ( 
        x 
        ) 
       
     
    {\textstyle a(x)\leq t\leq b(x)} 
   
 
  
    
      
        
          x 
          
            0 
           
         
        ≤ 
        x 
        ≤ 
        
          x 
          
            1 
           
         
       
     
    {\textstyle x_{0}\leq x\leq x_{1}} 
   
 
  
    
      
        a 
        ( 
        x 
        ) 
       
     
    {\textstyle a(x)} 
   
 
  
    
      
        b 
        ( 
        x 
        ) 
       
     
    {\textstyle b(x)} 
   
 
  
    
      
        
          x 
          
            0 
           
         
        ≤ 
        x 
        ≤ 
        
          x 
          
            1 
           
         
       
     
    {\textstyle x_{0}\leq x\leq x_{1}} 
   
 
  
    
      
        
          x 
          
            0 
           
         
        ≤ 
        x 
        ≤ 
        
          x 
          
            1 
           
         
       
     
    {\textstyle \,x_{0}\leq x\leq x_{1}} 
   
 
  
    
      
        
          F 
          ′ 
         
        ( 
        x 
        ) 
        = 
        f 
        ( 
        x 
        , 
        b 
        ( 
        x 
        ) 
        ) 
        
          b 
          ′ 
         
        ( 
        x 
        ) 
        − 
        f 
        ( 
        x 
        , 
        a 
        ( 
        x 
        ) 
        ) 
        
          a 
          ′ 
         
        ( 
        x 
        ) 
        + 
        
          ∫ 
          
            a 
            ( 
            x 
            ) 
           
          
            b 
            ( 
            x 
            ) 
           
         
        
          
            ∂ 
            
              ∂ 
              x 
             
           
         
        f 
        ( 
        x 
        , 
        t 
        ) 
        d 
        t 
        . 
       
     
    {\displaystyle F'(x)=f(x,b(x))\,b'(x)-f(x,a(x))\,a'(x)+\int _{a(x)}^{b(x)}{\frac {\partial }{\partial x}}\,f(x,t)\;dt\,.} 
   
 
This formula is the general form of the Leibniz integral rule  and can be derived using the fundamental theorem of calculus .
Derivatives to n th order 
Some rules exist for computing the 
  
    
      
        n 
       
     
    {\textstyle n} 
   
 
  
    
      
        n 
       
     
    {\textstyle n} 
   
 
If 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        n 
       
     
    {\textstyle n} 
   
 
  
    
      
        
          
            
              d 
              
                n 
               
             
            
              d 
              
                x 
                
                  n 
                 
               
             
           
         
        [ 
        f 
        ( 
        g 
        ( 
        x 
        ) 
        ) 
        ] 
        = 
        n 
        ! 
        
          ∑ 
          
            { 
            
              k 
              
                m 
               
             
            } 
           
         
        
          f 
          
            ( 
            r 
            ) 
           
         
        ( 
        g 
        ( 
        x 
        ) 
        ) 
        
          ∏ 
          
            m 
            = 
            1 
           
          
            n 
           
         
        
          
            1 
            
              
                k 
                
                  m 
                 
               
              ! 
             
           
         
        
          
            ( 
            
              
                g 
                
                  ( 
                  m 
                  ) 
                 
               
              ( 
              x 
              ) 
             
            ) 
           
          
            
              k 
              
                m 
               
             
           
         
        , 
       
     
    {\displaystyle {\frac {d^{n}}{dx^{n}}}[f(g(x))]=n!\sum _{\{k_{m}\}}f^{(r)}(g(x))\prod _{m=1}^{n}{\frac {1}{k_{m}!}}\left(g^{(m)}(x)\right)^{k_{m}},} 
   
 
  
    
      
        r 
        = 
        
          ∑ 
          
            m 
            = 
            1 
           
          
            n 
            − 
            1 
           
         
        
          k 
          
            m 
           
         
       
     
    {\textstyle r=\sum _{m=1}^{n-1}k_{m}} 
   
 
  
    
      
        { 
        
          k 
          
            m 
           
         
        } 
       
     
    {\textstyle \{k_{m}\}} 
   
 Diophantine equation  
  
    
      
        
          ∑ 
          
            m 
            = 
            1 
           
          
            n 
           
         
        m 
        
          k 
          
            m 
           
         
        = 
        n 
       
     
    {\textstyle \sum _{m=1}^{n}mk_{m}=n} 
   
 
General Leibniz rule 
If 
  
    
      
        f 
       
     
    {\textstyle f} 
   
 
  
    
      
        g 
       
     
    {\textstyle g} 
   
 
  
    
      
        n 
       
     
    {\textstyle n} 
   
 
  
    
      
        
          
            
              d 
              
                n 
               
             
            
              d 
              
                x 
                
                  n 
                 
               
             
           
         
        [ 
        f 
        ( 
        x 
        ) 
        g 
        ( 
        x 
        ) 
        ] 
        = 
        
          ∑ 
          
            k 
            = 
            0 
           
          
            n 
           
         
        
          
            
              ( 
             
            
              n 
              k 
             
            
              ) 
             
           
         
        
          
            
              d 
              
                n 
                − 
                k 
               
             
            
              d 
              
                x 
                
                  n 
                  − 
                  k 
                 
               
             
           
         
        f 
        ( 
        x 
        ) 
        
          
            
              d 
              
                k 
               
             
            
              d 
              
                x 
                
                  k 
                 
               
             
           
         
        g 
        ( 
        x 
        ) 
        . 
       
     
    {\displaystyle {\frac {d^{n}}{dx^{n}}}[f(x)g(x)]=\sum _{k=0}^{n}{\binom {n}{k}}{\frac {d^{n-k}}{dx^{n-k}}}f(x){\frac {d^{k}}{dx^{k}}}g(x).} 
   
 
See also 
References 
^ Calculus (5th edition) , F. Ayres, E. Mendelson, Schaum's Outline Series, 2009, ISBN  978-0-07-150861-2 .^ Advanced Calculus (3rd edition) , R. Wrede, M.R. Spiegel, Schaum's Outline Series, 2010, ISBN  978-0-07-162366-7 .^ Complex Variables , M.R. Spiegel, S. Lipschutz, J.J. Schiller, D. Spellman, Schaum's Outlines Series, McGraw Hill (USA), 2009, ISBN  978-0-07-161569-3 ^ "Differentiation Rules" . University of Waterloo – CEMC Open Courseware . Retrieved 3 May  2022 .  
Sources and further reading 
These rules are given in many books, both on elementary and advanced calculus, in pure and applied mathematics. Those in this article (in addition to the above references) can be found in:
Mathematical Handbook of Formulas and Tables (3rd edition) , S. Lipschutz, M.R. Spiegel, J. Liu, Schaum's Outline Series, 2009, ISBN  978-0-07-154855-7 .The Cambridge Handbook of Physics Formulas , G. Woan, Cambridge University Press, 2010, ISBN  978-0-521-57507-2 .Mathematical methods for physics and engineering , K.F. Riley, M.P. Hobson, S.J. Bence, Cambridge University Press, 2010, ISBN  978-0-521-86153-3 NIST Handbook of Mathematical Functions , F. W. J. Olver, D. W. Lozier, R. F. Boisvert, C. W. Clark, Cambridge University Press, 2010, ISBN  978-0-521-19225-5 .
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