Completing Your Graph
Now you can find the turning point easily since it sits on the line of symmetry at x = -1. Substitute this back into your equation: y = (-1)² + 2(-1) - 8 = -9. Your turning point is at (-1, -9).
For the y-intercept, simply set x = 0 in your equation. This gives you y = 0² + 2(0) - 8 = -8, so your y-intercept is at (0, -8).
You now have everything needed to sketch your graph: roots at (-4, 0) and (2, 0), turning point at (-1, -9), and y-intercept at (0, -8). Adding a couple of extra points like (-5, 7) and (3, 7) helps create that perfect U-shape.
Remember: Quadratic graphs are always symmetrical, so if you plot one side correctly, the other side mirrors it perfectly!