MathematicsMedium66×since 2002Q4084If cos−1x−cos−1y2=α,{\cos ^{ - 1}}x - {\cos ^{ - 1}}{y \over 2} = \alpha ,cos−1x−cos−12y=α, then 4x2−4xycosα+y24{x^2} - 4xy\cos \alpha + {y^2}4x2−4xycosα+y2 is equal to :A2sin2α2\sin 2\alpha2sin2αB444C4sin2α4{\sin ^2}\alpha4sin2αD−4sin2α-4{\sin ^2}\alpha−4sin2αCheck answerSkip