hardnstrong wrote:
Bunuel wrote:
hardnstrong wrote:
If x ≠ 0, what is the value of sq. root (x^u/x^v) ?
(1) u = v
(2) x is a perfect square.
OA will be posted later
\sqrt{\frac{x^u}{x^v}}=?(1)
u=v -->
\sqrt{\frac{x^u}{x^v}}=\sqrt{\frac{x^u}{x^u}}=\sqrt{1}=1. Sufficient.
(2) x is a perfect square --> Clearly not sufficient.
Answer: A.
my question is sq. root of 1 can be +1 or -1 (
like sq, root of 4 can be +2 or -2)
How can it be only 1?
please explain
OA is A
Any nonnegative real number has a
unique non-negative square root called
the principal square root and unless otherwise specified,
the square root is generally taken to mean
the principal square root.
When the GMAT provides the square root sign for an even root, such as
\sqrt{x} or
\sqrt[4]{x}, then the
only accepted answer is the positive root.
That is,
\sqrt{25}=5, NOT +5 or -5. In contrast, the equation
x^2=25 has TWO solutions, +5 and -5.
Even roots have only non-negative value on the GMAT.Odd roots will have the same sign as the base of the root. For example,
\sqrt[3]{125} =5 and
\sqrt[3]{-64} =-4.
Hope it helps.
_________________
NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders
COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!
DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!, 11 New DS set. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
close
83% (02:12) correct
