If a line makes an angle of `pi/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 (1) `pi/6` (2) `pi/3` (3) `pi/4` (4) `pi/2`

Explanation

If`l,m,n`is direction of a line then

`l^2+m^2+n^2=0`

and if line make`(alpha
,beta,gamma)`with Co-ordinate xis

`l=Cosalpha`

`m=Cosbeta`

`n=Cosgamma`

`Cos^2alpha+Cos^2beta+Cos^2gamma=1`

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