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F(x) = x2 + 2x – 15. What are the x-intercepts of the function?

1 Answer

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Answer:

X-intercepts at x = -5 and x = 3

Explanation:

To solve this, you first need to know that x-intercepts occurs at the "zeros" of the function. In other words, the x-values you get when you make y (aka f(x)) equal 0. If you don't like to look at the function and do logical factoring, you can always rely on the quadratic formula too; it will never lead you wrong. For me I just did logical factoring in my head and got (x+5)(x-3). The last step, because remember this is set equal to zero, is to get the x-values x = -5 and x = 3. Hope this helps!

User Stefan Jung
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