Question

What is the vertex form of `y= x^2-6x-21`?

Answer 1

`y = (x - 3)^2 - 30`

Explanation:

x-coordinate of vertex:
`x = -b/(2a) = 6/2 = 3`
y-coordinate of vertex:
`y (3) = 9 - 18 - 21 = - 30`
Vertex form: `y = (x - 3)^2 - 30`