here is a thing that helps you find the vertex, axis of symmetry, and minimum/maximum of a parabola. put in the three constants of your parabola, A B and C, and it does everything else for you! ax^2+bx+c form is the only one in it at the moment however...
Edit: forgot to add the link: https://www.desmos.com/calculator/8fw95te13x
Melody: I just added the link in properly.