Question 389594: Find the x-intercepts of the parabola with vertex of (-2,-8) and y-intercepts of (0,4).I have no Idea how to solve this please help. Answer by ewatrrr(10682) (Show Source):
Hi,
the vertex form of a parabola, where(h,k) is the vertex
vertex (-2,-8)
y =a(x+2)^2 -8
using y-intercept pt(0,4) to find a
4 = a(-2)^2 -8
12 = 4a
3 = a
y = 3(x+2)^2 -8
finding x-intercepts when y = 0
0 = 3(x^2 + 4x + 4) -8
0 = 3x^2 + 12x + 4
Present these x values as is traditional for your classroom
