Question

What are the x intercepts of the graph of the function below y=x^2-2x-15

Answer 1

x = -3 and x = 5.

Explanation:

y = x^2 - 2x - 15

y = (x - 5)(x + 3)

The x-intercepts occur when y = 0. In this case, it's when either (x - 5) = 0, or (x + 3) = 0.

x - 5 = 0

x = 5

x + 3 = 0

x = -3

Hope this helps!

Answer 2

(5, 0) and (-3, 0)

Explanation:

To find the x-intercepts, let's set y = 0.

0 = x² - 2x - 15

0 = (x - 5)(x + 3) -- To factor x² - 2x - 15, we need to find 2 numbers with a sum of -2 and product of -15; these numbers are -5 and 3.

x - 5 = 0 or x + 3 = 0 -- Use ZPP (Zero Product Property)

x = 5, x = -3