- (4, 5) and (4, -2) -
We can find the slope by using rise/run
![m=(y_2-y_1)/(x_2-x_1)\\m=(5-(-2))/(4-4) \\](https://img.qammunity.org/2021/formulas/mathematics/high-school/72tihr9n2zvyzexwotkr97rzz3ogjf3bci.png)
As expected, the slope is indeed undefined. The denominator can't be 0 but this one has denominator that's 0 which is undefined.
Meaning that, when the x-value for both ordered pairs are the same, the slope will be undefined.
For the graph, It should be like this below in the picture.