COORDINATE ISSUES!!!!! HELP ASAP

Expert replies

AIM TO CRACK GMAT: Senior | Next Rank: 100 Posts; Posts: 80; Joined: Sat Sep 15, 2012 1:07 amFollowed by: 1 member; Thanked: 1 times

by AIM TO CRACK GMAT » Tue Oct 15, 2013 6:02 am

Hi everyone!

This is a problem from MGMATs Strategy Guides Geometry

Q- The line represented by the equation y= x is the perpendicular bisector of line segment AB, IF A has the coordinates (-3,3) What are the Coordinates of B????

[spoiler]OA= (3,-3)[/spoiler]

Like this post

Source: Beat The GMAT — Problem Solving | Tue Oct 15, 2013 6:02 am

theCodeToGMAT: Legendary Member; Posts: 1556; Joined: Tue Aug 14, 2012 11:18 pmFollowed by: 34 members; Thanked: 448 times; GMAT Score:650

by theCodeToGMAT » Tue Oct 15, 2013 6:21 am

Please post Answer Choices

R A H U L

Like this post

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 » Tue Oct 15, 2013 6:30 am

Because the GMAT would provide answer choices, we typically can solve this sort of problem by DRAWING:

https://www.beatthegmat.com/grockit-toug ... 74452.html
https://www.beatthegmat.com/og-12-t77036.html
https://www.beatthegmat.com/cant-form-th ... 67741.html

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

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Tue Oct 15, 2013 6:36 am

AIM TO CRACK GMAT wrote:Hi everyone!

This is a problem from MGMATs Strategy Guides Geometry

Q- The line represented by the equation y= x is the perpendicular bisector of line segment AB, IF A has the coordinates (-3,3) What are the Coordinates of B????

[spoiler]OA= (3,-3)[/spoiler]

Saying that line represented by equation y = x is the perpendicular bisector of line segment AB, is a fancy way of saying that point B is a mirror reflection of point A across the line y = x (in other words, the mirror is the line y = x).

This concept is probably beyond the scope of the GMAT, but if some point (a,b) is reflected across the line y = x, the reflected point is (b,a).
Example: if the point (9,2) is reflected across the line y = x, the reflected point is (2,9)

The question basically tells us that the point (-3, 3) is reflected across the line y = x, so the reflected point (point B) is at [spoiler](3, -3) [/spoiler]

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

AIM TO CRACK GMAT: Senior | Next Rank: 100 Posts; Posts: 80; Joined: Sat Sep 15, 2012 1:07 amFollowed by: 1 member; Thanked: 1 times

by AIM TO CRACK GMAT » Tue Oct 15, 2013 6:45 am

Hi... There r no answer choices... this is a problem given in the Problem set at the end of the chapter!!

theCodeToGMAT wrote:Please post Answer Choices

Like this post

mevicks: Master | Next Rank: 500 Posts; Posts: 269; Joined: Thu Sep 19, 2013 12:46 amFollowed by: 7 members; Thanked: 94 times

by mevicks » Tue Oct 15, 2013 7:06 am

AIM TO CRACK GMAT wrote:Hi everyone!

This is a problem from MGMATs Strategy Guides Geometry

Q- The line represented by the equation y= x is the perpendicular bisector of line segment AB, IF A has the coordinates (-3,3) What are the Coordinates of B????

[spoiler]OA= (3,-3)[/spoiler]

You can use the basic Reflection property to find the co-ordinates. Here is the quick drawing:

Since A is equidistant from both the axises, the perpendicular from A would pass through the origin into the IVth quadrant, where the co-ordinates would be reversed to (3, -3)

There is a algebraic approach too, but I think it would not be required on the GMAT!

Regards,
Vivek

Regards,
Vivek

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 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