equation of a graph that includes points (-1,3) (0, -1) ans (1,3)

Question

i need to find the equation of the parabola with those points

Answer 1

(0,-1), (1,3), (-1,3)

vertex is (0,-1)

y=ax^2 -1

3= a -1

a= 4

y= 4x^2 -1