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Write Direction Cosines of a Line Parallel to Z-axis. - Mathematics

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Question

Write direction cosines of a line parallel to z-axis.

Sum
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Solution

A line parallel to zaxis, makes an angle of 90°, 90° and 0° with the x, y and z axes, respectively.

Thus, the direction cosines are given by

l = cos 90° =0

 m = cos 90° = 0 

n = cos 0 =1

Therefore, direction cosines of a line parallel to the zaxis are 0, 0, 1.

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Chapter 27: Direction Cosines and Direction Ratios - Very Short Answers [Page 25]

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RD Sharma Mathematics [English] Class 12
Chapter 27 Direction Cosines and Direction Ratios
Very Short Answers | Q 18 | Page 25

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