Answer: y = -14/9(x + 4)^2 + 7
Step-by-step explanation:
The given roots of the quadratic function is (-1, -7)
The vertex is at (-4, 7)
The formula is
y = a(x - h)^2 + k
The vertex is (h, k)
Comparing with the given vertex, (-4, 7), h = -4 and k = 7
Substituting into the formula
y = a(x - h)^2 + k, it becomes
y = a(x - - 4)^2 + 7
y = a(x + 4)^2 + 7
From the roots given (-1, -7)
x = -1 and y = -7
Substituting x = -1 and y = -7 into the equation,
y = a(x + 4)^2 + 7, it becomes
-7 = a(-1+4)^2 + 7
-7 = a(3^2 ) + 7
- 7 = 9a + 7
-7-7 = 9a
9a = -14
a = -14/9
Substituting a = - 14/9 into the equation, it becomes
y = -14/9(x + 4)^2 + 7