Question

Write the direction cosine of a line equally inclined to the three coordinate axes.

Answer 1

Any line equally inclined to coordinate axes will have direction cosines l, l, l

\(\therefore\) \(l^2+l^2+l^2 =1\)

\(3l^2=1\)

\(\Rightarrow l = \pm \frac{1}{\sqrt{3}}\)

\(\therefore\) Direction cosines are