What is sin^2theta/(1-tantheta) sin2θ1tanθ in terms of costhetacosθ?

1 Answer
Mar 3, 2016

costheta((1−cos^2theta))/(costheta-sqrt(1−cos^2theta))cosθ(1cos2θ)cosθ1cos2θ

Explanation:

sin^2theta/(1−tantheta)sin2θ1tanθ can be written in term of costhetacosθ, using identities

sin^2theta=1−cos^2thetasin2θ=1cos2θ i.e. sintheta=sqrt(1−cos^2theta)sinθ=1cos2θ

and tantheta=sintheta/costhetatanθ=sinθcosθ

As such sin^2theta/(1−tantheta)sin2θ1tanθ

= (1−cos^2theta)/(1-sintheta/costheta)1cos2θ1sinθcosθ

Multi[lying numerator and denominator by costhetacosθ, we get

costheta((1−cos^2theta))/(costheta-sintheta)cosθ(1cos2θ)cosθsinθ or

costheta((1−cos^2theta))/(costheta-sqrt(1−cos^2theta))cosθ(1cos2θ)cosθ1cos2θ