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20 votes
20 votes
Find the x-intercepts of the parabola with

vertex (-3,405) and y-intercept (0,360).
Write your answer in this form: (X₁,Y₁), (X2,₂).
If necessary, round to the nearest hundredth.
Enter the correct answer.

Find the x-intercepts of the parabola with vertex (-3,405) and y-intercept (0,360). Write-example-1
User Nicholas Tulach
by
2.6k points

1 Answer

22 votes
22 votes

Answer: (-12, 0) and (6, 0)

Explanation:

The equation of the parabola is of the form


y=a(x+3)^2 + 405. To find a, we can substitute in the coordinates (0,360).


360=a(0+3)^2 + 405\\\\360=9a+405\\\\-45=9a\\\\a=-5

So, the equation is
y=-5(x+3)^2 + 405. Setting this equal to 0,


-5(x+3)^2 + 405=0\\\\5(x+3)^2 = 405\\\\(x+3)^2 = 81\\x+3=\pm 9\\\\x=-12, 6

So, the x-intercepts are (-12, 0) and (6, 0).

Find the x-intercepts of the parabola with vertex (-3,405) and y-intercept (0,360). Write-example-1
User Jay Godse
by
2.9k points