Write the equation of a line with an undefined slope and point (3, 10)

Hey 

The in order to find the equation of an undefined slope you need to understand what slope is. Slope is defined as the change of y over the change of x. or in other words y2-y1/x2-x1. If a slope is positive then the line rises up from left to right. If the slope is negative then the line falls downward from ,left to right. If the slope is zero, then the line is horizontal since there is no rise. If the slope is undefined then the line is vertical since there is no run. Thus, a vertical line passing through the point (3,10) is 3. 

Hope you understand. :)

Note:

A slope of zero is a horizontal line. This is parallel to the x axis.

An undefined slope is a vertical line. This is parallel to the y axis.

So for the line to have undefined slope and pass through (3, 10)

The line will be parallel to the y axis,

So the line in this case is  x = 3. This is so that it also passes through (3, 10)

The line is x = 3.