Point P is at and we know that when x = 3.

The distance between point P and (2, 0) is

So

So when x = 3 the distance is changing at a rate of

The angle of the line segment formed by this distance is characterized by the slope between the two points:

(I know this isn't standard form, but I'm just going to leave it like this for now.)

Now, geometrically speaking

where is the angle of inclination.

So

Now,

.

Thus

(I'm tired. I'll let you plug in x = 3.)

-Dan