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If a line makes an angle of 30°, 60°, 90° with the positive direction of x, y, z-axes, respectively, then find its direction cosines. - Mathematics

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Question

If a line makes an angle of 30°, 60°, 90° with the positive direction of x, y, z-axes, respectively, then find its direction cosines.

Sum
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Solution

The direction cosines of a line which makes an angle of α, β, γ with the axes, are cosα, cosβ, cosγ

Therefore, D.C.’s of the line are cos30°, cos60°, cos90°

i.e., `+(sqrt(3)/2, 1/2, 0)`

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Chapter 11: Three Dimensional Geometry - Solved Examples [Page 225]

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NCERT Exemplar Mathematics [English] Class 12
Chapter 11 Three Dimensional Geometry
Solved Examples | Q 3 | Page 225

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