If tan^4θ - tan^2θ = 1 ; then cot^4θ + cot^2θ = ?

1 Answer
Jun 19, 2017

cot^4 theta+cot^2theta=1

Explanation:

tan^4 theta-tan^2theta=1 or tan^4 theta=tan^2theta+1 or tan^4 theta = sec^2theta or sin^4 theta/cos^4 theta=1/cos^2theta or

sin^4 theta/cos^2 theta=1 or cos^2theta/sin^4theta=1

cot^4 theta+cot^2theta=cot^2theta(1+cot^2theta)

= cot^2theta*csc^2theta= cos^2theta/sin^2theta*1/sin^2 theta

=cos^2theta/sin^4 theta= 1

:. cot^4 theta+cot^2theta=1 [Ans]