Question

How do you find the vertex of the parabola by completing the square `x^2-6x+8=y`?

Answer 1

`y=x^2-6x+8=x^2-6x+9-1=(x-3)^2-1`

This has its vertex where `x-3 = 0`, that is `x=3`.

When `x=3` we have `y = 0^2-1 = -1`

So the vertex is at `(3, -1)`