Question

Which of the following equations that have a graph in which the parabola opens downward.

y = 2x2 + 2x + 8

y = −4x2 + 8x − 19

y = 16x2 + 2x − 4

y = −x2 − 6x + 10

Answer 1

If the coefficient on the x^2 is negative, then the parabola opens downward, so the answer is:
y = -4x^2 + 8x - 19
y = -x^2 - 6x + 10

Answer 2

:D!