what if u have y intercept and 2 points?

Answer 1

The parabola is y = ax^2 + bx + C where

(s,t) and (m,n) are the points on the parabola with y-intercept (0,C)

Then

t = as^2 + bs + C

n = am^2 + bm + C

is a 2x2 that can be solved by substitution or elimination.