Question

If sin theta=1/√3,then cos 2 theta
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Answer 1

Formula for-:

Formula for-:cos 2θ = 1 - 2sin^2 θ

given,

sin θ = 1/√3

squaring both sides

sin^2 θ = 1/3

now,

cos 2θ = 1 - 2(1/3)

cos 2θ = 1 - 2/3

cos 2θ = (3 - 2) / 3

cos 2θ = 1/3

Answer 2

Step-by-step explanation:

tan theta=1/√3

tan theta=30°

=cos2theta

=cos2(√3/2)

=cos√3

-√3=cos