Complete a table with at least 5 points then graph the following quadratic on the coordinate plane. Identify all the zeros. Y=-2x^2+5x+8

Question

I’m not sure how to do this but it has to do something with completing the square

Answer 1

Complete a table with at least 5 points then graph the following quadratic on the coordinate plane. Identify all the zeros. Y = -2x² + 5x + 8

Actually, the easiest way to calculate this is to use the quadratic formula, since it is already in standard form. So:

1. A = -2, B = 5 and C = 8, enter into the quadratic equation
2. (-5 ± √(5² - 4(-2)(8)))/2(-2)
3. (-5 ± √(25 - -64))/-4
4. (-5 ± √89)/-4
5. X ≅ 1.1085; X ≅ 3.6085

Answer 2

You don't need to do any completing the square. Pick x-values, ug them in, find the y-value, and graph.

y = -2(-1)² + 5(-1) + 8

y = -2 - 5 + 8

y = 1

(-1,1) is one point.