Question

If the line makes angle $\frac{\pi }{6}$ and $\frac{\pi }{3}$ with positive direction of x and y axes respectively, then it makes with z-axis is

• A. π/6
• B. π/4
• C. π/3
• D. π/2

Answer 1

The correct option is D

π/2

$co{s}^2\alpha +co{s}^2\beta +co{s}^2\gamma =1\Rightarrow \frac{3}{4}+\frac{1}{4}+co{s}^2\gamma =1\Rightarrow cos\gamma =0\Rightarrow \gamma =\frac{\pi }{2}$