A line makes angles `angle, beta, gamma and delta` with the diagonals of a cube. Show that `cos^(2)alpha+cos^(2)beta+cos^(2)gamma+cos^(2)delta=4//3`.

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 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

A line makes acute angles of alpha, beta and gamma with the co-ordinae axes such that cos alpha cos beta = cos beta cos gamma = (2)/(9) and cos gamma cos alpha = (4)/(9), then cos alpha + cos beta + cos gamma is equal to : a) (25)/(9) b) (5)/(9) c) (5)/(3) d) (2)/(3)

If a straight line makes angles alpha,beta,gamma with the coordinate axes, then (1-"tan"^(2)alpha)/(1+"tan"^(2)alpha)+1/("sec"2beta)-2"sin"^(2)gamma is equal to

If a line makes alpha,beta,gamma with x,y,z axis respectively, then prove that sin^2alpha+sin^2beta+sin^2gamma=2

If cot alpha cot beta=2 , show that (cos (alpha+beta))/(cos (alpha-beta))=(1)/(3)