If cos^(-1)x-"cos"^(-1)(y)/(2)=alpha, t...

If `cos^(-1)x-"cos"^(-1)(y)/(2)=alpha`, then `4x^(2)-4xy cos alpha+y^(2)` is equal to :

A

(a) `-4sin^(2)alpha`

B

(b) `4sin^(2)alpha`

C

(c) 4

D

(d) `2sin^(2)alpha`

Verified by Experts

The correct Answer is:

B

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