The angle between the two planes 3x-4y+5z =0 and 2x-y-2z=5 is

If α ,β, γ are the angles which a half ray makes with the positive directions of the axes , then
sin²α + sin²β + sin²γ =

If the direction ratios of a line are 1,-3,2 ;then its direction cosines are

The angle between the planes 2x - y + z =6 and x + y + 2z = 7 is

The direction cosines of any normal to the XY-plane are

The point which divides the line joining the points (2,4,5) and (3,5,-4) in the ratio -2:3 lies on

If A(1,2,3) , B(-1,-1,-1) be the points ,then the distance AB is