Question

Simplify the following expression. cot^2 x sec x-cos x

Answer 1

like a first step you need to know that sec x = 1/cos x

cot x = cos x / sin x so

cot^2 x = cos^2 x / sin^2 x

using these above wrote you can rewriting the given equation in this form

cot^2 x sec x - cos x =

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

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

= [cos x /(1-cos^2 x)] - cos x

hope helped