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 Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

That was rather a quick reply, thanx. I'll post the OA as and when i get some more replies. However, I have just a couple of questions

1) Why do we not sovle this problem by simply backsolving and determining the option which returns the least value using the equation? Why are you finding out the range?

2) In your solution, why have u changed the inequality sign in "z<-3/2" ?
ie. shouldng it be z>-3/2 or z>1/2 ?...but even then this range doesnt make sense.

3) One question regarding how to use this forum more effectively: how do i set an email alert when i wish to track all the replies that are posted to this question. There is an option "Notify me when a reply is posted". But i am notified when i get only one reply!

Re: PS - Value of z [#permalink]
19 Oct 2005, 09:50

cdaat wrote:

What is the minimum value of z for which (z^2)+z-(3/4)>0 is not true?

(A) -5/2 (B) -3/2 (C) -1/2 (D) 1/4 (E) 1/2

z^+z-3/4=(z+1/2)^2-1
It>0 is not true means it has to be less or equal to 0.
(z+1/2)^2-1<=0
(z+1/2)^2<=1
-1<=z+1/2<=1
-3/2<=z<=1/2
The minimum value of z is thus -3/2. _________________

Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.

Last edited by HongHu on 19 Oct 2005, 09:58, edited 1 time in total.

I went about solving the problem a little different.

Because the question asked for the least values I decided to plug in the second least value and solve. I would have adjusted my next value based on the answer i received. Because i got =0. I didnt' go any further.

It isn't very technical but it made it quick to solve.

I went about solving the problem a little different.

Because the question asked for the least values I decided to plug in the second least value and solve. I would have adjusted my next value based on the answer i received. Because i got =0. I didnt' go any further.

It isn't very technical but it made it quick to solve.

agree, this one is ok and not too complicated, you can definitely plug and play

Yes. I often make such errors, oops. Let it be an example for you not to do it in the real test.

Unfortunately Mr. Honghu such errors are the bane of my existence.

hmmm.... Are you sure Honghu is Mr.?

It's 'Ms.' !

Oops! My bad. A thousand apologies Ms. Honghu. Apparently, my data sufficiency skills for real life situations has not kept pace with the gmat.

Heh maybe I'm just a Mr HongHu pretending to be a Ms HongHu so that my mistakes are more easily tolerated ... Isn't real life more interesting and complicated. _________________

Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.

Re: What is the minimum value of z for which z^2+z-3/4>0 [#permalink]
29 Oct 2011, 01:03

On solving the equation we get (2z+3)(2z-1)>0. The critical points for the above equation will be -3/2 and 1/2 (where value of z=0).

Now let us find put 3 no's in the equation- 2 which lie on either side of the critical points and 1 in between.

Lets say -2,0 and 2. *On filling -2 in the equation we get 5/4 which is +ve.(no number within this range (-infinity to -3/4) will satisfy the condition as they all will be more than 0)

*On filling 0 in the equation we get -3/4 which is -ve

*On filling 2 we get 21/4 which is +ve.(no number within this range (1/2 to +infinity) will satisfy the condition as they all will be more than 0)

We can safely eliminate a and c options.

Now at -3/2 and 1/2 we know value is 0. Let us check at 1/4. Value at 1/4 = -9/16 = -0.56.

Question clearly says minimum value of z where equation>0 is not true. so it means value can be 0 or less than 0. We need to find the minimum value of z and not of the equation where the condition holds. out of -3/2,1/4 and 1/2 minimum value where the condition will not be true is -3/2. Hence option b.

Hope it helps...

gmatclubot

Re: What is the minimum value of z for which z^2+z-3/4>0
[#permalink]
29 Oct 2011, 01:03

: Social ventures, both non-profits and for-profits, seek to better the world in such industries as education, microfinance, workforce development, public health and community development, among others. Organizations that...

Essay B for Stanford GSB will essentially ask you to explain why you’re doing what you’re doing. Namely, the essay wants to know, A) why you’re seeking...

Over the last week my Facebook wall has been flooded with most positive, almost euphoric emotions: “End of a fantastic school year”, “What a life-changing year it’s been”, “My...