hello :
note :
1 ) f(X0) = Y0 equiv : X0 = f^-1(Y0)
2 ) ( f^-1(Y0) )' = 1/ f'(X0)
in this exercice : X0 = 0
he equation of the tangent line for graph of : f
Y - Y0 = f'(X0) (X- 0)
sp : he equation of the tangent line for graph of : f^-1(x) is :
X -X0 = f'(Y0) (Y -0)
