To find the slope of the perpendicular line, we must find the slope of the line with x-intercept of 2 and y-intercept of -4.
Let's use rise/run to find the slope. The run is 2, and the rise if 4 (yes, positive 4).
4/2 = 2
So, the slope of the original line is 2. The other line must have a slope that is the negative reciprocal of that, which will be -1/2.
Let's start making our equation by using point-slope form.
For a line with slope m and that passes through

, the point slope form equation is the following:

We know the passing point and the slope. Now, let's plug them into the point-slope form formula.

Distribute.

Now, add both sides by 4.

Replace y with f(x)
