Question

The solution set of $cos2\theta =co{s}^2\theta$ is

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

$cos2\theta =co{s}^2\theta \Rightarrow 2co{s}^2\theta -1=co{s}^2\theta \Rightarrow co{s}^2\theta =1\Rightarrow \theta =n\pi ;nϵZ$