Question

How do you find the VERTEX of a parabola `y=-x^2+4x+12`?

Answer 1

I found:
`x_v=2`
`y_v=16`

Explanation:

You could use the derivative (setting it equal to zero to find the `x` coordinate of the vertex) but I am not sure you know the derivative so, instead, you can find the `x` coordinate using the relationship:
`x_v=-b/(2a)`
using your equation in the form `y=ax^2+bx+c` where:
`a=-1`
`b=4`
`c=12` you get:
`x_v=-4/(-2)=2`
Substituting back this value into your equation you get:
`y_v=-4+8+12=16`