Question

Write the slope of the line which is parallel to $x$-axis.

Answer 1

Inclination of $x-$ axis is $0^0$. Slope of two or more parallel lines is the same or equal to each other.
Hence, inclination of a line which is parallel to x-axis is $0^0$.
Slope of line with an inclination $\theta =$ tan $\theta$.
Hence, slope of line, with inclination $\theta$ $=0^0$ is tan $0^0=0$.