Question

What is the vertex of `y=(x +3)^2 -6x`?

Answer 1

`V = (0, 9)`

Explanation:

If `y = ax^2 + bx + c` then `V = (-b/(2a), - Delta/(4a))`

`y = x^2 + 6x + 9 - 6x`
`a = 1, b = 0, c = 9`
`Delta = 0^2 - 4 * 1 * 9 = -36`