Set 15: Quadratic Equations (Intermediate)

Choice A is correct. Choice A is the correct answer. The vertex $(h, k)$ is found by first calculating the x-coordinate $h = -b/2 a$. 1. $h = -8 / (2 \times 2) = -8 / 4 = -2$. 2. Substitute $x = -2$ back into the equation to find $y$: $y = 2(-2)^2 + 8(-2) - 3$ $y = 2(4) - 16 - 3$ $y = 8 - 16 - 3 = -11$. So the vertex is $(-2, -11)$. Choice B is incorrect because it uses $x=2$. Choice C is incorrect because it assumes the y-intercept (-3) is the y-coordinate of the vertex. Choice D is incorrect because it calculates x incorrectly.