Question

Algebraically, determine the values of "a" and "b" in the relation y = ax^2 + bx - 13 if the vertex is located at (-4, 3).

Answer 1

you know that

y = a(x+4)^2 + 3 = ax^2 + 8ax + 16a+3
so you know that 16x+3 = -13
so a = -1
and that means that
y = -x^2 - 8x - 13
a = -1
b = -8