Question

How do you prove `-tan^2x+sec^2x=sec^2xcos^2x`?

Answer 1

It is an identity to be proved.

Explanation:

LHS is =`-sin^2 x/ cos^2 x + 1/ cos^2 x`
= `(-sin^2 x +1)/cos^2 x`
= `cos^2 x/ cos^2 x`
=`sec^2 x cos^2 x`= RHS