Question

What is the vertex form of `y = 3x^2 + 9x − 4`?

Answer 1

y = (x + 3/2)^2 - 43/4

Explanation:

x-coordinate of vertex:
`x = -b/(2a) = -9/6 = -3/2.`
y-coordinate of vertex:
`y(-3/2) = 3(9/4) - 9(3/2) - 4 = 27/4 - 27/2 - 4 = -43/4`
Vertex form: `y = (x + 3/2)^2 - 43/4`