Write an equation of the parabola in vertex form that passes through (−7, −15) and has vertex (−5, 9)

Answer 1

Vertex form:

y = a·(x-h)² + k

where (h, k) is the location of the vertex. In your case (h, k) = (-5,9) so:

y = a·(x-(-5))² + 9 = a·(x+5)² + 9

To find the value of the constant a, plug in the given point (-7, -15):

y = a·(x+5)² + 9

-15 = a·(-7+5)² + 9

Solve for a