Question

Find the x-intercepts of the parabola with vertex (-3,-18) and y-intercept at (0,0)

Answer 1

Y + 18 = a(x + 3)^2 
0 + 18 = a(0 + 3)^2 
18 = 9a 
2 = a 

y = 2(x + 3)^2 - 18 
0 = 2(x + 3)^2 - 18 
18 = 2(x + 3)^2 
9 = (x + 3)^2 
± 3 = x + 3 
-3 ± 3 = x 
x = 0 or -6 

(0, 0) and (-6, 0)