How do you find an equation of a quadratic function from two points. The two points are the vertex and the y intercept.

Question

Suppose you have y=ax^2 + bx + c
The vertex occurs when x satisifes 2ax+b=0 or x=-b/(2a)
The y intercept occurs at x=0, so it's the c component.
Do you have a specific problem you're solving?