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

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Answer 1 · 2016-11-26T07:14:37

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

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

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

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

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

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