Bunuel
If 0 < x < 1, which of the following is the greatest?
A. \(x^{(-\frac{1}{2})}\)
B. \(x^0\)
C. \(x^{(\frac{1}{2})}\)
D. \(x^1\)
E. \(x^2\)
If 0 < x < 1, it is a proper fraction, (e.g., \(\frac{1}{2}\)).
Number propertiesIf very fluent in properties of these fractions, finding the answer is quick and no calculations are needed:
The
negative exponent with the
smallest value will yield the greatest answer. Only choice A has a negative exponent.
Given their equal absolute values, you could compare Answer A and Answer C (see below for calculation) to be sure.
After that or at a glance, the greatest result is
Answer A
Test a valueBecause the answer choices contain square roots, and to keep things simple, choose a
unit fraction whose denominator is a perfect square, e.g. \(\frac{1}{9}\)
A. \((\frac{1}{9})^{(-\frac{1}{2})}\) =\(9^{(\frac{1}{2})}\) = \(\sqrt{9} =\\
3\)
B. \((\frac{1}{9})^0\) = 1
C.\((\frac{1}{9})^{(\frac{1}{2})}\) =\(\sqrt{\frac{1}{9}}\) = \(\frac{1}{3}\)
D. \((\frac{1}{9})^1\) = \(\frac{1}{9}\)
E. \((\frac{1}{9})^2\) = \(\frac{1}{81}\)
Greatest of these results?
ANSWER A