Question

Question #de3d6

Answer 1

`tan^2a-cot^2a-1=0`

Explanation:

If we take the given expression:

`tan^4a-tan^2a=1`

and divide by `rtan^2a` then we get:

`tan^4a/tan^2a-tan^2a/tan^2a=1/tan^2a`

`:. tan^2a-1=cot^2a`

`:. tan^2a-cot^2a-1=0`