William W. answered 12/16/19
Experienced Tutor and Retired Engineer
I think you have your x's and y's mixed around. An ordered pair is (x, y) where the first number is the x and the second number is the y.
I THINK you mean that the places the parabola crosses the x-axis are (-5, 0) and (-3, 0) and that the vertex is at the point (-4, -2). So the parabola looks like this:
Based on that assumption, I can answer the question.
The zeroes are the places the parabola crosses the x-axis. So, the zeros are x = -5 and x = -3
The equation of the parabola can be determined using the vertex form of a quadratic function which is
y = a(x - h)2 + k where the point (h, k) is the vertex and the value "a" is the stretch factor. we can plug in the vertex values (h and k) to get:
y = a(x - -4)2 + -2 or
y = a(x + 4)2 - 2
To calculate the value of "a", we can plug in one of the ordered pairs we have from the zeros, I'll pick (-5, 0). So we plug in x = -5 and y = 0 to get:
0 = a(-5 + 4)2 - 2
2 = a(-1)2
2 = a
So the equation for the parabola is y = 2(x + 4)2 - 2