Continuity question - Math Help Forum

$Math Help Forum$

$Go Back$		Math Help Forum > Pre-University Math Help > Pre-Calculus
$Reload this Page$ Continuity question

Download MHF Flyer

Mark Forums Read

$Reply$

#1

$Old$ July 3rd, 2009, 09:14 AM

champrock $champrock is offline$

Member

Join Date: Nov 2008

Posts: 169

Country:

India

Thanks: 50

Thanked 1 Time in 1 Post

$champrock is on a distinguished road$

$Default$ Continuity question

Hi

Analyse the continuity of the function
z = (xy-5)/(x^2+y^2-4)

I checked that z approaches infinity when x^2+y^2=4 so, this circle represents the discontinuity points. Is this right?

Thanks

$Reply With Quote$

Advertisement

#2

$Old$ July 3rd, 2009, 11:49 AM

HallsofIvy $HallsofIvy is online now$

MHF Contributor

Join Date: Apr 2005

Posts: 3,489

Thanks: 324

Thanked 1,212 Times in 1,113 Posts

$HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$ $HallsofIvy has much to be proud of$

$Default$

Yes, that is correct. This function is continuous everywhere except on the circle $x^2+ y^2= 4$ .

$Reply With Quote$

#3

$Old$ July 3rd, 2009, 12:10 PM

running-gag $running-gag is offline$

MHF Contributor

Join Date: Nov 2008

Posts: 1,135

Country:

France

Thanks: 39

Thanked 542 Times in 505 Posts

$running-gag is a name known to all$ $running-gag is a name known to all$ $running-gag is a name known to all$ $running-gag is a name known to all$ $running-gag is a name known to all$ $running-gag is a name known to all$

$Default$

You need to check that there are no points on the circle where xy = 5

$Reply With Quote$

$Reply$

« Limits of two variables | Top | Area of a Rectangle »

Thread Tools
$Show Printable Version$ Show Printable Version $Email this Page$ Email this Page
Display Modes
$Linear Mode$ Linear Mode $Hybrid Mode$ Switch to Hybrid Mode $Threaded Mode$ Switch to Threaded Mode

Posting Rules
You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are Off

Forum Jump

All times are GMT -7. The time now is 05:52 AM.

your link here Sponsors

rv solar, e-learning,

Math Help Forum is a community of maths forums with an emphasis on maths help in all levels of mathematics.
Register to post your math questions or just hang out and try some of our math games or visit the arcade.