If `alpha+beta+gamma=2pi`, prove that : `cos^2 alpha + cos^2 beta + cos^2 gamma-2cosalpha cosbeta cosgamma=1`.

If alpha + beta+gamma=pi , prove that sin^2 alpha + sin^ beta - sin^2 gamma = 2sinalpha sinbeta cosgamma

If alpha+beta=gamma prove that cos^(2)alpha+cos^(2)beta+cos^(2)gamma=1+2cos alpha cos beta cos gamma

If cos alpha+cos beta+cos gamma=0; then prove that cos3 alpha+cos3 beta+cos3 gamma=12cos alpha cos beta cos gamma

If cos alpha+cos beta+cos gamma=0, then prove that cos3 alpha+cos3 beta+cos3 gamma=12cos alpha cos beta cos gamma

If alpha + beta- gamma= pi , prove that sin^(2)alpha + sin^(2)beta - sin^(2)gamma = 2sin alpha sin beta cos gamma .

Given alpha+beta-gamma=pi, prove that sin^(2)alpha+sin^(2)beta-sin^(2)gamma=2sin alpha sin beta cos gamma

Given alpha+beta-gamma=pi, prove that sin^(2)alpha+sin^(2)beta-sin^(2)gamma=2sin alpha sin beta cos gamma

cos^(2) alpha +cos^(2) beta +cos^(2) gamma is equal to

If alpha+beta= 60^0 , prove that cos^2 alpha + cos^2 beta - cosalpha cos beta = 3/4 .