Question

Find the slope of the line passing through the points (3,-9) and (3,9)

Answer 1

We find the slope as follows:

`m=(9-(-9))/(3-(3))\Rightarrow m=\infty`

So, the line is a vertical line.

***

To find the slope of two points we use the following expression:

`m=(y_2-y_1)/(x_2-x_1)`

In this function, there are points (x1, y1) & (x2, y2).

If the values in the denominator are equal [As in the problem given] this means that the slope will be divided by 0 and therefore is not defined [Or infinite]. Since we can see that x1 = x2 that means that the line keeps moving but the x-coordinate of each point is located at x = 3 and the only values that vary are the y-components. The line given is the following:

So, its slope is undefined and that means the line is vertical.