You need to find the equation of a function that satisfies:
f(4)= -18
f(4)=-18
If you calculate the slope of the line using the formula:
And the given ordered pairs (4,-18) and (4,-18)
You'll determine that the slope of the line is equal to zero.
Lines with slope zero are horizontal, which means that regardless of the value of x, the value of y will remain the same.
In this case, this value is the y-coordinate of the given ordered pairs y=-18
So the equation of the line, expressed using function notation is: