if f(4)=7 and f'(4)=2/5 find (f^-1)(7)

Answer 1

I think you must be looking for (f^-1) ' (7) if not, you don't need f '(4)

If f(4) = 7 then f^-1(7) = 4 so (f-1) ' (7) = 1/f '(f^-1(7)) = 1/f '(4) = 1/(2/5) = 5/2