Question

Question #452ac

Answer 1

Explained below.

Explanation:

It would be easier to prove RHS equal to LHS. Accordingly,

RHS=`1/(cos 2x) - (2tan x)/ (1-tan^2x)`

=`1/(cos^2 x - sin^2 x) - (2sin x cosx)/(cos^2x - sin^2x)`

=`(1- 2sinx cos x)/(cos^2 x - sin^2 x)`

=`(cosx-sin x)^2 /((cosx-sin x)(cos x+ sin x))`

=`(cosx- sinx)/(cos x+ sin x)` =LHS