Posted by Mary on Wednesday, March 20, 2013 at 4:42pm.
with respect to x
f(cos x) if f'(x)= 1/x
find (f(cos x))'
i got tan x sec x
this is wrong.
please explain. thank you

Derivative  Steve, Wednesday, March 20, 2013 at 5:18pm
if f'(x) = 1/x
f(cos x)' = 1/cosx * sinx = tanx