The area bounded by the curves |x + y| = 1 and |x - y| = 1 - The Beat The GMAT Forum

The area bounded by the curves |x + y| = 1 and |x - y| = 1

Expert replies

Vincen: Legendary Member; Posts: 2898; Joined: Thu Sep 07, 2017 2:49 pmFollowed by: 5 members; Thanked: 6 times

by Vincen » Fri Sep 08, 2017 2:51 pm

The area bounded by the curves |x + y| = 1 and |x - y| = 1 is

A. 3
B. 4
C. 2
D. 1
E. None

The OA is C.

Can I do this exercise without making the graph of the curves? I mean, only with the equations?

Like this post

Source: Beat The GMAT — Problem Solving | Fri Sep 08, 2017 2:51 pm

GMAT/MBA Expert

Jay@ManhattanReview: GMAT Instructor; Posts: 3008; Joined: Mon Aug 22, 2016 6:19 amFollowed by: 34 members; Location: Grand Central / New York; Thanked: 470 times

by Jay@ManhattanReview » Sat Sep 09, 2017 12:14 am

Vincen wrote:The area bounded by the curves |x + y| = 1 and |x - y| = 1 is

A. 3
B. 4
C. 2
D. 1
E. None

The OA is C.

Can I do this exercise without making the graph of the curves? I mean, only with the equations?

Well, I would not suggest that you go for equation method. It will take more time, though it can be done. With the help of the equations you will find the coordinates of 4 points and then you will have to calculate the distances between the points to find out the length of the area.

Plotting the lines on a coordinate plane is easier than you think.

We have |x + y| = 1. This gives two straight lines: x + y = 1 and x + y = -1

We also have |x - y| = 1. This gives two straight lines: x - y = 1 and x - y = -1

Once you plot these 4 straight lines, you can find the length of diagonals and then the sides of the square, thereby area of the square = 2.

The correct answer: C

Hope this helps!

Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Jakarta | Nanjing | Berlin | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

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