How do you write y=x^2+7x-1 in vertex form?

1 Answer
Jul 30, 2016

y = (x + 7/2)^2 - 53/4

Explanation:

x-coordinate of vertex:
x = -b/(2a) = -7/2
y-coordinate of vertex (when x = -7/2):
y(-7/2) = 49/4 - 7(7/2) - 1 = 49/4 - 49/2 - 1 = -53/4
Vertex (-7/2, -53/4)
Vertex form of y:
y = a(x + b/(2a)) + y(-b/(2a))
y = (x + 7/2)^2 - 53/4