Question

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

Answer 1

`(-color(red)(9/2)|color(green)(-69/4))`

Explanation:

`y=x^2+9x+3`
`y=x^2+2*9/2x+(9/2)^2-(9/2)^2+3`
`y=(x+9/2)^2-81/4+3`
`y=(x+color(red)(9/2))^2color(green)(-69/4)`

The vertex is at `(-color(red)(9/2)|color(green)(-69/4))`