GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Jul 2018, 06:58

### 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

# I never learned functions and how to approach them, when i

Author Message
Senior Manager
Joined: 04 Aug 2008
Posts: 363
I never learned functions and how to approach them, when i  [#permalink]

### Show Tags

28 Sep 2008, 16:39
I never learned functions and how to approach them, when i see f(x) my brain gets paralized and freezes up. Here is the question (i guessed right tho

For which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?

f(x) = x^2
f(x) =x+1
f(x) =sqrt of x
f(x) = 2/x
f(x) = -3x

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________

The one who flies is worthy. The one who is worthy flies. The one who doesn't fly isn't worthy

Manager
Joined: 22 Sep 2008
Posts: 117

### Show Tags

28 Sep 2008, 17:37
Hi

f(x) = -3x .

f(a+b) = -3 (a+b) = -3a -3b --------------1

f(a) + f(b) = -3a + (-b) = -3a -3b ---------2

1 = 2

does GMAT ask this type of questions?
VP
Joined: 05 Jul 2008
Posts: 1331

### Show Tags

28 Sep 2008, 22:09
vr4indian wrote:
Hi

f(x) = -3x .

f(a+b) = -3 (a+b) = -3a -3b --------------1

f(a) + f(b) = -3a + (-b) = -3a -3b ---------2

1 = 2

does GMAT ask this type of questions?

I believe these questions appear on the test. there was a similar q yesterday that was posted here. the key here is to figure out that we have to substitute (a+b), a and b respectively for the functions.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: Functions nightmare &nbs [#permalink] 28 Sep 2008, 22:09
Display posts from previous: Sort by

# I never learned functions and how to approach them, when i

Moderator: chetan2u

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.