Question

What are the direction cosines of Z-axis?

Answer 1

$$\begin{gathered} \mathrm{The}z-\mathrm{axis}\mathrm{makes}\mathrm{angles}90°,90°\mathrm{and}0°\mathrm{with}\mathit{}x\mathit{,}\mathit{}y\mathrm{and}\mathit{}z\mathrm{axes},\mathrm{respectively}. \\ \mathrm{Therefore},\mathrm{the}\mathrm{direction}\mathrm{cosines}\mathrm{of}z-\mathrm{axis}\mathrm{are}\cos 90°,\cos 90°,\cos 0°,\mathrm{i}.\mathrm{e}.0,0,1. \end{gathered}$$