Prove that cot^2x-cos^2x=cot^2xcos^2x?

2 Answers
Mar 22, 2017

Please see below.

Explanation:

cot^2x-cos^2x

= cos^2x/sin^2x-cos^2x

= (cos^2x-cos^2xsin^2x)/sin^2x

= (cos^2x(1-sin^2x))/sin^2x

= (cos^2x xxcos^2x)/sin^2x

= (cos^2x/sin^2x xxcos^2x)

= cot^2xcos^2x

Mar 22, 2017

Develop the left side:
LS = (cos^2 x)/(sin^2 x) - cos ^2 x = ((cos^2 x)(1 - sin^2 x))/(sin^2 x) =
= (cos^2 x.cos^2 x)/(sin^2 x) = cot^2 x.cos^2 x Proved.