For the function f(x)=x^3+2x-1, find (f^-1)'(2) (or: find the derivative of the inverse of f(x) at x = 2).
2 answers
take a look how I did your similar type of question a few posts above this
Recall that if g(x) is the inverse of f(x) then
if f(a) = b then g'(b) = 1/f'(a)
f(1) = 2
so g'(2) = 1/f'(1) = 1/5
if f(a) = b then g'(b) = 1/f'(a)
f(1) = 2
so g'(2) = 1/f'(1) = 1/5