y=ax? +bx+c
=a[x+b/(2a)]? +(4ac-b? )/(4a)
So: Vertex coordinates (-b/(2a), (4ac-b? )/(4a))
Parabolic vertex
y=a(x-n)(x-m)
So the symmetry axis is x=(m+n)/2.
So [(m+n)/2, -a (m-n) 2/4]