Question

What is the vertex form of `-y=x^2+4x+5`?

Answer 1

`y = (x + 2)^2 - 1.`

Explanation:

`y = - x^2 - 4x - 5`
x-coordinate of vertex:
`x = -b/(2a) = 4/(-2) = -2`
y-coordinate of vertex:
y(-2) = - 4 + 8 - 5 = -1
Vertex form: `y = (x + 2)^2 - 1`
graph{- x^2 - 4x - 5 [-10, 10, -5, 5]}