Question

Help pls, answer choices listed!

what is the standard form of the quadratic function that has a vertex of (4,-2)and goes through the point ( 5,0)
A. y = 2x^2 - 16x + 30
B. y = 2x^2 - 16x + 32
C. y= 2 (x - 4)^2 - 2
D. y = 2x^2 - 8x - 2

Answer 1

C: y = 2(x - 4) - 2

Explanation:

The vertex formula of a quadratic is y - k = m(x - h).

Here the vertex is at (4, -2), and so we now have y + 2 = a(x - 4).

Find a: letting y = 0 and x = 5, we get 0 + 2 = a(5 - 4), which means a = 2.

The desired equation is C: y = 2(x - 4) - 2