Question

sintheta + sin²theta=1 show that cos²theta +cos4theta
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Answer 1

Answer:

[tex]Given, sinθ+sin2θ=1

⇒sinθ=1−sin2θ=cos2θ

Therefore, cos2θ+cos4θ=cos2θ(1+cos2θ)

=sinθ(1+sinθ)

=sinθ+sin2θ

=1

hope it helps you