Dear Bunuel,
Hope you are doing well. I just wanted to check that in option II x>0, can I say it is actually an invalid option? My logic is that because the range of x is greater than 1 or less than -1, so, x>0 will include values like 0.5, 0.1 and for those |x|>x^2. Hence, we cannot say may or maybe true.
Kindly let me know if my logic is correct.
Thank you!
Best,
Komal
Bunuel
If \(|x| < x^2\), which of the following must be true?
I. \(x^2 > 1\)
II. \(x > 0\)
III. \(x < -1\)
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) I and III only
Given: \(|x|<x^2\);
Reduce by \(|x|\): \(1<|x|\) (side note: we can safely do this as absolute value is non-negative and in this case we know it's not zero too, as if x would be zero inequality wouldn't hold true, so \(|x|>0\));
So we have that \(x<-1\) or \(x>1\).
I. \(x^2>1\) --> always true;
II. \(x>0\) --> may or may not be true;
III. \(x<-1\) --> may or may not be true.
Answer: A (I only).