" If "cos alpha+cos beta=0=sin alpha+sin beta," then "cos2 alpha+cos2 beta=

If cos alpha+cos beta=0=sin alpha+sinbeta, then cos2alpha+cos 2beta=

If cos alpha+cos beta=0=sin alpha+sin beta , then cos 2 alpha+cos 2beta is equal to

If cos alpha + cos beta =0 = sin alpha + sin beta , then cos 2 alpha + cos 2 beta is equal to

If cos alpha + cos beta =0 = sin alpha + sin beta " then " cos (alpha - beta )=

If cos alpha+cos beta=0=sin alpha+sin beta. Prove that cos2 alpha+cos2 beta=-2cos(alpha+beta)

If cos alpha+cos beta=0=sin alpha+sin beta, then prove that cos2 alpha+cos2 beta=-2cos(alpha+beta)

If cos alpha+cos beta=0=sin alpha+sin beta, then prove that cos2 alpha+cos2 beta=-2cos(alpha+beta)

If cos alpha + cos beta = 0 = sin alpha + sin beta, then value of cos 2 alpha + cos 2 beta is

A = [[0, sin alpha, sin alpha sin beta-sin alpha, 0, cos alpha cos beta-sin alpha sin beta, -cos alpha cos beta, 0]]