Question

What is the vertex form of `y=4x^2 + 8x − 19`?

Answer 1

`(-1,-23)`

Explanation:

The vertex equation is:
`x_v=(-b)/(2a)`

for these function,
`x_v=(-8)/(2*4)=-1`

now we substitute `x` by `-1` in the function equation,
`f(-1)=4·(-1)^2+8·(-1)-19=-23`

so the vertex is point `(-1,-23)`.