If `cos^-1 x-cos^-1 y=alpha,` then `x^2+y^2-2xy cos alpha` is equal to

If cos^-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,t h e n4x^2-4x ycosalpha+y^2 is equal to 4 (b) 2sin^2alpha (c) -4sin^2alpha (d) 4sin^2alpha

If cos^(-1)x-cos^(-1)y/2=alpha,t h e n4x^2-4x ycosalpha+y^2 is equal to (a)4 (b) 2sin^2alpha (c) -4sin^2alpha (d) 4sin^2alpha

If cos^(-1)x-cos^(-1)y/2=alpha,t h e n4x^2-4x ycosalpha+y^2 is equal to 4 (b) 2sin^2alpha (c) -4sin^2alpha (d) 4sin^2alpha

If cos^(-1)x-cos^(-1)y/2=alpha,t h e n4x^2-4x ycosalpha+y^2 is equal to 4 (b) 2sin^2alpha (c) -4sin^2alpha (d) 4sin^2alpha

If cos^(-1)x-cos^(-1)(y/2)=alpha,t h e n4x^2-4x ycosalpha+y^2 is equal to 4 (b) 2sin^2alpha (c) -4sin^2alpha (d) 4sin^2alpha

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