We have points (-1,3),(0,1),(1,3) so we can set up a system of equations for the general form ax^2+bx+c...
a+b+c=3, 0a+0b+c=1, a-b+c=3 getting differences
a+b=2, -a+b=-2 getting the sum
2b=0, b=0, making a+b=2 become:
a+0=2, a=2, making a+b+c=3 become:
2+0+c=3, c=1 so
y=2x^2+1
