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

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

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

If cos^(-1)x-cos^(-1)((y)/(2))=alpha then 4x^(2)-4xy cos alpha+y^(2)=

If cos^(-1)x- cos^(-1)""(y)/2 = alpha , then 4x^2 -4xycos alpha +y^2 is equal a) 2 sin alpha b)4 c) 4 sin^2alpha d) -4 sin^2alpha

If cos^(- 1)x-cos^(- 1)(y/2)=alpha then 4x^2-4xycosalpha+y^2=

If Cos^(-1)x-Cos^(-1)(y/2)=alpha" then "4x^(2)-4xycosalpha+y^(2)=

If cos^(- 1)x-cos^(- 1)(y/2)=alpha then 4x^2-4xycosalpha+y^2=