Notice that you are given the derivative equation. That means you can calculate the slope at any given point.
So if you were to draw a line segment starting at (0, 4) with slope of −8, what would be the coordinate point at x = 0.5?
Use the coordinate point (0.5, ______) to calculate a new slope and find the coordinate point at x = 1.
Do the same to find the coordinate at x = 1.5
And again at x = 2.