Question

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L
Find the x-intercepts of the parabola with
vertex (-1,-17) and y-intercept (0,-13).
Write your answer in this form: (*1,91),(X2,42).

Answer 1

1. (√30 - 1, 0)
2. (-√30 - 1, 0)

Explanation:

Making the equation of the parabola :

⇒ y = a(x - h)² + k

⇒ y = (x + 1)² - 17 - 13

⇒ y = (x + 1)² - 30

x-intercepts have y = 0 :

• 0 = (x + 1)² - 30
• (x + 1)² = 30

Taking the square root on each side :

• √(x + 1)² = √30
• x + 1 = ±√30
• x = ±√30 - 1

The x-intercepts are :

1. (√30 - 1, 0)
2. (-√30 - 1, 0)