A quadratic function has x-intercepts 2 and 6 and its vertex is (4, 8). What is the corresponding quadratic expression?

Answer 1

Obviously y = a(x-2)(x-6)
Since y(4) = 8, a = -2 and

y = -2(x-2)(x-6)
= -2((x-4)^2 - 4)
= -2x^2 + 16x - 24