Question

How do you write the equation of a line through points (-1,4), (-1, 7.2)?

Answer 1

See below for an explanation!!

Explanation:

The line is a vertical line at `x=-1`. To prove this, we'll find the slope. The formula for this is

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

where `(x_1,y_1)` is `(-1,4)` and `(y_1,y_2)` is `(-1,7.2)`.Let's put in values and find the slope:

`(7.2-4)/(-1-(-1))=3.2/(-1+1)=3.2/0`

We can't divide by 0! What does this mean? The slope is undefined, so the line will be vertical. The two points that the line passes through are located at the x-value of `-1`. Therefore, the equation of the line is `x=-1`.

Hope this helped!