Question

${\tan }^4\theta +{\tan }^2\theta ={\sec }^4\theta -{\sec }^2\theta$

• A. True
• B. False

Answer 1

The correct option is A True

L.H.S. :

${\tan }^4\theta +{\tan }^2\theta$

$={\tan }^2\theta ({\tan }^2\theta +1)$

$=({\sec }^2\theta -1)({\tan }^2\theta +1)$

$=({\sec }^2\theta -1){\sec }^2\theta$

$={\sec }^4\theta -{\sec }^2\theta$ = RHS