Short Answer TypeA line makes an angle of 
with each of y-axis and z-axis. Find the angle made by it with x-axis.
The x-axis makes angles 0°, 90° and 90° with x, y and z-axis.
∴ direction cosines of x-axis are cos 0°, cos 90°, cos 90° i.e. 1, 0. 0
Again y-axis makes angles 90°, 0°, 90° with x, y and z-axis.
∴ direction cosines of y-axes are cos 90°, cos 0°, cos 90° i.e. 0, 1,0.
Also z-axis makes angles 90°, 90°, 0° with x, y and z-axis.
∴ direction cosines of z-axis and cos 90°, cos 90°, cos 0° i.e. 0, 0, 1.
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