Question

How do you write `y = -16x^2+40x+4` into vertex form?

Answer 1

Vertex form for a parabola is
`y=m(x-a)^2+b`
with the vertex at `(a,b)`

Re-arranging `y=16x^2+40x+4` into vertex form:

`y=-16(x^2-5/2x) +4 " extract the "m" factor"`

`y=-16(x^2-5/2x+(5/4)^2) +25 +4 " complete the square"`

`y = -16(x-5/4)^2+29`