Question
Prove the following.
$tan^4\theta + tan^2\theta = sec^4\theta - sec^2\theta$
 

Answer

Taking LHS
$tan^4\theta + tan^2\theta$
$= tan^2\theta ( tan^2\theta + 1)$
$= (sec^2\theta - 1)(sec^2\theta ) [1 + tan^2\theta = sec^2\theta ]$
$= sec^4\theta - sec^2\theta$
= RHS
Proved !

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free