Question

How do you simplify `f(theta)=cos^2theta-sin^2(2theta)`?

Answer 1

`f(theta)=cos^2theta(1-4sin^2theta)`

Explanation:

`f(theta)=cos^2theta-sin^2(2theta)`

= `cos^2theta-(2sinthetacostheta)^2`

= `cos^2theta-4sin^2thetacos^2theta`

= `cos^2theta(1-4sin^2theta)`