Parabola equation with a vertex at (h, k) is given by y = a(x - h)^2 + k For the give parabola, y = a(x - 4)^2 - 3 y = a(x^2 - 8x + 16) - 3 At (5, -6) -6 = a((5)^2 - 8(5) + 16) - 3 = a(25 - 40 + 16) - 3 = a - 3 a = -6 + 3 = -3
Therefore, the coefficient of the squared expression is -3.
