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  1. The value of
    3cosθ + cos3θ
    		is equal to
    3sinθ - sin3θ

    1. tanθθ
    2. cotθθ
    3. sinθθ
    4. cosθθ
Correct Option: B

3cosθ + cos3θ
3sinθ - sin3θ

=
3cosθ + 4 cos³θ - cos3θ
3sinθ - (3sinθ - 4sin³θ)

∵ cos3θ = 4cos³θ – 3cosθ
sin3θ = 3sinθ – 4sin³θ
=
4cos³θ
 = cot³θ
4sin³θ


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