Question

Suppose a parabola has vertex (-8, -7) and also passes through the point (-7,-4). Write the equation of the parabola invertex form

Answer 1

y = 3(x + 8)² - 7

Explanation:

y = a(x - -8)² - 7

y = a(x + 8)² - 7

-4 = a(-7 + 8)² - 7

3 = a

y = 3(x + 8)² - 7

Answer 2

y = 3 (x+8)^2 -7

Explanation:

The vertex form of the equation is

y = a(x-h)^2 +k

where (h,k) is the vertex

y = a (x- -8)^2 + -7

y = a (x+8)^2 -7

Now substitute the point into the equation to determine a

-4 = a (-7+8)^2 -7

-4 = a (1^2) -7

-4 = a -7

Add 7 to each side

-4+7 = a-7+7

3 =a

y = 3 (x+8)^2 -7