Question

What is the slope and intercept for `x=9`?

Answer 1

The line has an infinite slope and there is no y intercept, only an x intercept at `(9,0)`.

Explanation:

This is the equation of a vertical line.

The slope of a line is defined as the change in y divided by the change in x so

slope`= (Deltay)/(Deltax) = ( y_2 - y_1)/(x_2 - x_1`

`x_1 = 9`

`x_2 = 9`

`9-9 = 0" "` Dividing by zero equals infinity or is undefined. so

`(y_2 - y_1)/0` = infinity, an undefined value.

( try dividing by zero on a calculator)

Also since the line goes straight up from the point `(9,0)` it will never cross the y-axis, hence there is no y-intercept.