How to find the equation of a line with one point and undefined slope?

We will use the concept of the equation of straight lines to find the equation of lines.

Answer: The equation of the line will be parallel to the y-axis and passing through the point.

Let us see how we will use the concept of the equation of straight lines to find the equation of lines.

Explanation:

Let us consider a point (a, b).

Undefined slope basically means that the slope is infinity which is the slope of the y-axis.

Hence, the equation of the line passing through the point (a, b) is x = a.