Hi
Find the X-intercepts of a parabola with the vertex at (-3,16)
and the Y-intercept at (0,-20)
Using the vertex form of a parabola,where(h,k) is the vertex
y = a(x+3)^2 +16
-20 = a * 9 + 16
-36 = 9a
-4 = a
y = -4(x+3)^2 +16
x-intercepts when y = 0
-4(x+3)^2 = -16
(x+3)^2 = 4
x+3 = ± 2
x = -3 ± 2 x = -5 and x = -1