y-k = a(x-h)² Equation of a parabola, where (h , k) are the coordinates of Vertex. Replace h & k by 0 and 1 respectively:
y-1 = a(x-0)² → y-1 = ax². To calculate a, plug in the given values of (-12,9)
19-1 = a(-12)² → 18 = 144a and a = 1/8, hence the equation becomes:
y-1 = (1/8).x² OR y = x²/8 + 1
