Use the parabola tool to graph the quadratic function
f(x) = -(x - 2)(x + 4)
Graph the parabola by first plotting its vertex and then plotting a second point on the parabola.
Your parabola should look like this image. The vertex is at (-1, 9), and you can use any of the x-intercepts (-4, 0) & (2, 0) or the y-intercept (0, 8) as a second point.