Question

if y =(1-u)/(1+u) and u = cos 2x, what is y' ?
a.2tanx sec ^2 x
b.2secx tan^2 x
c.-2tan x sec^2 x
d.-2secx tan^2 x

Answer 1

\[\frac{dy}{dx}=\frac{dy}{du}\frac{du}{dx}\] is what you need

Answer 2

first one is the right one