Sommaire



Calculons la dérivée :
         y    = acos(x)                             *  y = acos(x)
        
     cos(y)   = cos(acos(x))
    
     cos(y)   = x    
    
    (cos(y))' = (x)'  
       

    (-sin(y)) dy/dx = 1
    
    
               dy/dx =  1/(-sin(y))  
                     = -1/sin(y)                      *  y = acos(x)       
       
       d(acos(x))/dx = -1/sin(acos(x))
                                               *** sin(acos(x)) = sqrt(1-x**2) ***    
          (acos(x))' = -1/sqrt(1-x**2)
 *** sin(acos(x)) = sqrt(1-x**2) ***