Question

Hey guys, Im stuck on this problem.
Given f'(tanx)=tanx
what is f'(x) =
any advice will help thanks and i will give medals :)

Answer 1

okay i got it
its x/(1+x^2)

Answer 2

f'(tanx) = tanx/sec^2(x)
f'(x)= x/(1+x^2)

Answer 3

\(f'\color{red}{(tanx)}=\color{red}{tanx}\)
\(f'\color{red}{(you)}=\color{red}{you}\)
\(f'\color{red}{(me)}=\color{red}{me}\)
how about \(f'\color{red}{(x)}=\color{red}??\)