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43 votes
43 votes
Given f(x) = 10/x^2- 7x-30

which of the following is true?

(see attached image, it’s not A)

Given f(x) = 10/x^2- 7x-30 which of the following is true? (see attached image, it-example-1
User Oleg Golovanov
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2 Answers

27 votes
27 votes

Answer: f(x) is positive for all x<10

Proof of validity is shown below.

Given f(x) = 10/x^2- 7x-30 which of the following is true? (see attached image, it-example-1
User Daut
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2.6k points
18 votes
18 votes
It would be f(x) would be positive for all x>10. That is because when you factor the bottom part you get (x-10)(x+3). 10 would give you 0 at the bottom and that means the answer will be undefined. That means any number above 10 would make it positive.
User Neknek Mouh
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2.5k points