Sir I’m extremely, extremely grateful for your posts, this blog has helped me immensely and I’m going to follow it even after my CAT this year because I’m just a smarter person thanks to it! I’m looking forward to the circles plotting post, sir! Would be lovely if you post it anytime soon. I have to write the CAT on the 7th, it would be simply brilliant to take the skills you share with me to the exam.

I did not understand the last question, how did you choose the x and y values to be +/-2? because when we solve the equation:
x+y+y-x = 4
we get y=1,
or
x+y+x-y = 4,
we get x = 1
or
-x-y+y-x = 4,
we get x= -1
or
-x-y-y+x = 4,
we get y = -1
so we get x=y= +/- 1.. plz help

I’m afraid not, as it is a single equation and not two separate equations. I won’t give you the precise answer, but I would urge you to plug in values of x and y and see for yourself (hint: it will be a square)

regards
J

Hi J,
As there is difference of two moduli, wont we get an infinite number of integral co-ordinates?

Ohh for that one. I thought you meant the question in the original post. Yeah, my bad, it will be a square for a plus sign in between the two modulus functions, not the minus 🙂 For the minus sign, you’re absolutely right and it won’t be an enclosed figure.

sir cat 2003 Q,it should be none of these,isnt it? maxima pt will be tending to infinity..minimum however would be 2.5…plz correct me if i’m wrong..

Yes Jaspreet, it should have been minimum. I will correct it!

regards

J

Sir I’m extremely, extremely grateful for your posts, this blog has helped me immensely and I’m going to follow it even after my CAT this year because I’m just a smarter person thanks to it! I’m looking forward to the circles plotting post, sir! Would be lovely if you post it anytime soon. I have to write the CAT on the 7th, it would be simply brilliant to take the skills you share with me to the exam.

Sincerely,

A CAT-holics fan.

I did not understand the last question, how did you choose the x and y values to be +/-2? because when we solve the equation:

x+y+y-x = 4

we get y=1,

or

x+y+x-y = 4,

we get x = 1

or

-x-y+y-x = 4,

we get x= -1

or

-x-y-y+x = 4,

we get y = -1

so we get x=y= +/- 1.. plz help

x+y+y-x = 4

=> 2y = 4

=> y = 2

Where’s the problem?

regards

J

oh yes.. sorry by mistake..

what about this question: find the area bounded by |x+y| – |x-y| = 4?

That would be 0 i think for the regions do not overlap..

I’m afraid not, as it is a single equation and not two separate equations. I won’t give you the precise answer, but I would urge you to plug in values of x and y and see for yourself (hint: it will be a square)

regards

J

Hi J,

As there is difference of two moduli, wont we get an infinite number of integral co-ordinates?

Not sure which question you’re asking about. Also, can you give me some examples of such infinite points, with larger values of x or y?

regards

J

For question : find the area bounded by |x+y| – |x-y| = 4.

(x,y) = (4,2), (5,2), (6,2), ………. ,(32,2), (34,2),……

Also, (-4,-2), (-5,-2), (-6,-2),………,(-32,-2), (-34,-2),…

Ohh for that one. I thought you meant the question in the original post. Yeah, my bad, it will be a square for a plus sign in between the two modulus functions, not the minus 🙂 For the minus sign, you’re absolutely right and it won’t be an enclosed figure.

regards

J