Question

Question #c7e5d

Answer 1

`sec^2(x-pi/4))`

Explanation:

`f=(cosx(tanx-1))/(cosx(tanx+1))`

`=(tanx-tan(pi/4))/(1+tanxtan(pi/4))`

`=tan(x-pi/4)`. So,

`f'=sec^2(x-pi/4)(x-pi/4)'=sec^2(x-pi/4)`