Correct ordering

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Correct ordering

by mshameen » Tue Feb 01, 2011 11:45 am
If x is positive, which of the following could be the correct ordering of 1/x, 2x, x^2?
I. x^2 < 2x < 1/x
II. x^2 < 1/x < 2x
III. 2x < x^2 < 1/x

A) None
B) I only
C) III only
D) I and II only
E) I, II, and III


For what value of x, could II be true? OA is D
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by aleph777 » Tue Feb 01, 2011 11:54 am
II could be true if x is 3/4, in which case

(3/4)^2 = 9/16

1/(3/4) = 4/3 (or 1.33)

2(3/4) = 6/4 = 1.5