Question

Find the quadratic function that has roots of -9 and 3 and a vertex of (-3,-36)

Answer 1

Y=(x+9)(x-3)+c
∵(-3,-36)lies on it.
-36=(-3+9)(-3-3)+c
-36=(-6)(-6)+c
-36=36+c
c=-36-36=-72
y=(x-9)(x+3)-72
y=x^2+3x-9x-27-72
y=x^2-6x-99