If a line makes angle `alpha, beta` and `gamma` with the coordinate axes respectively, then `cos2alpha+cos 2 beta+cos 2gamma=`

If a line makes angles alpha,beta and gamma with the coordinate axes,then prove that cos2 alpha+cos2 beta+cos2 gamma=-1

If a line makes angles alpha, beta, gamma with the coordinate axes, prove that cos2alpha + cos 2beta + cos2gamma + 1 = 0 .

If a line makes angles alpha ,beta , gamma with the co-ordinates axes, then cos 2alpha +cos 2beta +cos 2gamma is :

If a line in the space makes angles alpha, beta, " and " gamma with the coordinatess axes, then cos2alpha+cos2beta+cos2gamma+sin^(2)alpha+sin^(2)beta+sin^(2)gamma=

If a line in the space makes angle alpha,beta and gamma with the coordinate axes, then cos2alpha+cos2beta+cos2gamma+sin^2alpha+sin^2beta+sin^2gamma equals

If a line makes angle alpha,beta,gamma with the axes respectively, then cos 2alpha+cos 2beta + cos 2gamma =

If a line in the space makes angle alpha,beta and gamma with the coordinates axes, then cos^2alpha+cos^2beta+cos^2gamma is equal to a)1 b)2 c)0 d)3