Find the direction cosines of x, y and z-axis.

The correct answer is Option (1) → $(1, 0, 0), (0, 1, 0), (0, 0, 1)$ ##

The $x$-axis makes angles $0^\circ$, $90^\circ$ and $90^\circ$ respectively with $x$, $y$ and $z$-axis.

Therefore, the direction cosines of $x$-axis are $\cos 0^\circ$, $\cos 90^\circ$, $\cos 90^\circ$ i.e., $1, 0, 0$.

Similarly, direction cosines of $y$-axis and $z$-axis are $0, 1, 0$ and $0, 0, 1$ respectively.