Question

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

• A. 0
• B. 1
• C. -1
• D. Not defined

Answer 1

The correct option is D Not defined

Inclination of $y-$ axis is ${90}^0$. The slope of two or more parallel lines is the same or equal to each other.
Hence, the inclination of a line which is parallel to the y-axis is ${90}^0$.
Slope of line with an inclination $\theta =$ tan $\theta$.
Hence, slope of line, with inclination $\theta$ $={90}^0$ is tan ${90}^0=$ not defined.