-->

Three Dimensional Geometry

Question
CBSEENMA12036178

If a line makes an angle of π/4 with the positive directions of each of x-axis and y-axis, then the angle that the line makes with the positive direction of the z-axis is

  • π/6

  • π/3

  • π/4

  • π/2

Solution

D.

π/2

l = cos π/4 , m = cos π/4
we know l2 + m2 + n2 = 1
1 half space plus space 1 half space plus straight n squared space equals 1
rightwards double arrow space straight n space equals space 0
Hence angle with the positive direction of z-axis is π/2 .