Answer:
y = (x + 4.5)² - 13.25
Step-by-step explanation:
y = x² + 9x + 7
We need to get a perfectly squared binomial as part of the right side.
Take the '9x' term, divide it in half, square it, add <u>and also subtract it </u>on the right side, as shown below. That would be (4.5)² = 20.25 added <u>and </u>subtracted.
y = x² + 9x + 7
y = x² + 9x + 20.25 + 7 - 20.25
y = (x² + 9x + 20.25) - 13.25
y = (x + 4.5)² - 13.25
y = (x + 4.5)² - 13.25
Vertex Form is y = a(x-h)² + k, where the parabola vertex is (h, k)
So if you wrote this as y = 1(x - [-4.5] )² + (-13.25), we would see that a = 1, and h = -4.5 and k = -13.25.
Vertex = (-4.5, -13.25)
I verified on a graphing calculator that this is indeed the vertex of the parabola.
