If f(x) = (x + âˆš3)^4, what is the range of the function f(

Expert replies

vinni.k: Master | Next Rank: 500 Posts; Posts: 421; Joined: Sun Apr 17, 2011 4:27 amFollowed by: 2 members; Location: India; Thanked: 6 times; GMAT Score:620

by vinni.k » Wed Dec 05, 2012 2:07 am

Source:- MGMAT equations

If f(x) = (x + âˆš3)^4, what is the range of the function f(x) ?

A. âˆš3 < f(x) < 4
B. f(x) >= 0
C. f(x) < 0
D. f(x) not equal to 0

Answer is B

Why A cannot be the answer ?

Thanks & Regards
Vinni

Like this post

Source: Beat The GMAT — Problem Solving | Wed Dec 05, 2012 2:07 am

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Wed Dec 05, 2012 2:35 am

vinni.k wrote:Source:- MGMAT equations

If f(x) = (x + âˆš3)^4, what is the range of the function f(x) ?

A. âˆš3 < f(x) < 4
B. f(x) >= 0
C. f(x) < 0
D. f(x) not equal to 0

Answer is B

Why A cannot be the answer ?

Thanks & Regards
Vinni

The RANGE is composed of ALL possible values of f(x).
If x = -âˆš3, then f(-âˆš3) = (-âˆš3 + âˆš3)â�´ = 0.
Since the correct answer must include 0 within its range, eliminate A, C and D.

The correct answer is B.

(x + âˆš3)â�´ can be equal to any NONNEGATIVE value.
Thus, the range of f(x) = (x + âˆš3)â�´ is any value greater than or equal to 0.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Like this post

vinni.k: Master | Next Rank: 500 Posts; Posts: 421; Joined: Sun Apr 17, 2011 4:27 amFollowed by: 2 members; Location: India; Thanked: 6 times; GMAT Score:620

by vinni.k » Wed Dec 05, 2012 4:28 am

GMATGuruNY wrote: The RANGE is composed of ALL possible values of f(x).
If x = -âˆš3, then f(-âˆš3) = (-âˆš3 + âˆš3)â�´ = 0.
Since the correct answer must include 0 within its range, eliminate A, C and D.

The correct answer is B.

(x + âˆš3)â�´ can be equal to any NONNEGATIVE value.
Thus, the range of f(x) = (x + âˆš3)â�´ is any value greater than or equal to 0.

Thanks Mitch. As always you are the best. Making things easier to understand.

Regards
Vinni

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review