Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 29 May 2017, 14:54

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# practice problem

Author Message
TAGS:

### Hide Tags

Intern
Joined: 14 Jul 2003
Posts: 18
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

12 Aug 2003, 12:05
this is an actual practice problem i came across

if x = -1, what is -x^2?

is it 1 or -1?
Intern
Joined: 01 Aug 2003
Posts: 7
Location: California
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

12 Aug 2003, 12:11
goldsjo wrote:
this is an actual practice problem i came across

if x = -1, what is -x^2?

is it 1 or -1?

Any number (positive or negative) raised to an even power is positive.
Manager
Joined: 11 Mar 2003
Posts: 54
Location: Chicago
Followers: 1

Kudos [?]: 0 [0], given: 0

### Show Tags

13 Aug 2003, 17:31
Shouldn't this be -1? because x = -1

so -X^2 = -(-1)^2 = -1
Intern
Joined: 19 Jul 2003
Posts: 3
Location: taiwan
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

14 Aug 2003, 05:57
goldsjo wrote:
this is an actual practice problem i came across

if x = -1, what is -x^2?

is it 1 or -1?

Ans: -1

-(-1)^2= -1
Intern
Joined: 04 Aug 2003
Posts: 24
Location: Orange County
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

14 Aug 2003, 09:50
andy_taiwan wrote:
goldsjo wrote:
this is an actual practice problem i came across

if x = -1, what is -x^2?

is it 1 or -1?

Ans: -1

-(-1)^2= -1

I'm seeing two different answers here. Can someone confirm if its -1 or 1?
If you follow the logic that a negative x a negative = positive you get one. But if you follow the Order of operations, exponents come first and -*1 =
-1
Manager
Joined: 10 Jun 2003
Posts: 210
Location: Maryland
Followers: 2

Kudos [?]: 7 [0], given: 0

### Show Tags

14 Aug 2003, 10:40
Follow the order of operations and get -1. As it is written that is the correct answer.
Intern
Joined: 01 Aug 2003
Posts: 7
Location: California
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

14 Aug 2003, 11:43
Oops....I stand corrected. I fell for the trap. Sorry if I confused you. Everyone is right, the answer is -1. My apologies.
Manager
Joined: 28 Feb 2003
Posts: 147
Location: Kiev
Followers: 1

Kudos [?]: 9 [0], given: 0

### Show Tags

15 Aug 2003, 07:05
If x = -1 then -x^2=1 and -(x^2)=-1 !!!
GMAT Instructor
Joined: 07 Jul 2003
Posts: 770
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 26

Kudos [?]: 212 [0], given: 0

### Show Tags

15 Aug 2003, 07:54
goldsjo wrote:
this is an actual practice problem i came across

if x = -1, what is -x^2?

is it 1 or -1?

The interpretation of -x^2 as -(x^2) is correct according to agreements made by international math authorities. It is more convincing when it is typeset properly with the exponent as a superset number. Another way of getting this right is to substitute "(-1)*" for the "-".
Hence -x^2 = (-1)*x^2 and it is clearly (-1)*(x^2).

What makes this a somewhat confusing question is that: 1) most of the popular lists of algebraic precedence rules (e.g., PEMDAS) ignore the unary functions "+" and "-" when it should be properly placed below Exponentiation and above Multiplication/Division; and 2) one of the most widely used programs, Microsoft Excel, treats -x^y as (-x)^y on the spreadsheet. Try it! (The 600 pound gorilla acknowledges the "error" but has no intention of fixing it and possibly breaking millions of existing spreadsheets). Interestingly enough, the macro language built in Excel, VBA, treats -x^y properly as -(x^y).

just in case you were wondering....
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Re: practice problem   [#permalink] 15 Aug 2003, 07:54
Similar topics Replies Last post
Similar
Topics:
Gmat practice 0 09 Jun 2015, 02:16
was rockin out practice tests no problem but got bent over on test day 6 13 Jan 2015, 17:21
CR Practice 1 20 Dec 2008, 19:35
Problem with GMATprep 0 03 Dec 2007, 02:02
Practice CATs 1 30 Aug 2007, 09:32
Display posts from previous: Sort by