Question

What is the the vertex of `y =x^2+4x-7`?

Answer 1

Complete the square to find the vertex:

`(-2, -11)`

Explanation:

Complete the square:

`y = x^2+4x-7`

`= x^2+4x+4-11`

`= (x+2)^2-11`

This is an upright parabola with vertex at `(-2, -11)` where `(x+2)^2` takes its minimum possible value `0`.
graph{ x^2+4x-7 [-18.61, 13.43, -12.75, 3.28]}