Question

How do you prove `2sinthetacos^3theta+2sin^3thetacostheta=sin2theta`?

Answer 1

Please see below.

Explanation:

`2sinthetacos^3theta+2sin^3thetacostheta`

= `2sinthetacostheta(cos^2theta+sin^2theta)`

= `sin2thetaxx1`

= `sin2theta`