Find the equation of a parabola whose vertex is at (−1, 7), whose axis of symmetry is x = −1, and whose y-intercept is (0, 18). Write your answer in vertex form.
Vertex form of parabola
y =a (x+1)^2 + 7
= a ( x^2 + 2x + 1) a*1 + 7 must equal the y -axis intercept of 18 so a = 11
y = 11(x+1)^2 + 7
