SOLUTION: Find the x intercept of the parabola with vertex (-4,2) and y intercept (0,-30). Write the answer in this form (x1,y1) (x2,y2) . Round to the hundredth if necessary.

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Find the x intercept of the parabola with vertex (-4,2) and y intercept (0,-30). Write the answer in this form (x1,y1) (x2,y2) . Round to the hundredth if necessary.       Log On


   

Question 978905: Find the x intercept of the parabola with vertex (-4,2) and y intercept (0,-30). Write the answer in this form (x1,y1) (x2,y2) . Round to the hundredth if necessary.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
In vertex form,
y=a%28x-%28-4%29%29%5E2%2B2
y=a%28x%2B4%29%5E2%2B2
So then solving for the y-intercept,
-30=a%280%2B4%29%5E2%2B2
-30=16a%2B2
-32=16a
a=-2
So then,
y=-2%28x%2B4%29%5E2%2B2
Solving for the x-intercept,
0=-2%28x%2B4%29%5E2%2B2
-2=-2%28x%2B4%29%5E2
1=%28x%2B4%29%5E2
x%2B4=1 and x%2B4=-1
x=-3 and x=-5
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