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]