Question

If a line makes angles ${90}^{\circ }$, ${135}^{\circ }$, ${45}^{\circ }$ with the X, Y, and Z axes respectively, then find its product direction cosines.

Answer 1

Respective Direction cosines are $\cos {90}^o,\cos {135}^o,\cos {45}^o$

Since, $\cos {90}^o=0$

hence, The Product of three direction cosines $=0$