# TI 89 Graphing

• Nov 1st 2009, 02:26 PM
JohnDoe
TI 89 Graphing
Hello everyone,
I wonder if it is possible to graph |x|+|y|=x^2+y^2 function on TI89 Titanium if so can someone please provide me step-by-step instructions because I always get stuck with the "Undefined Variable" error. No matter what I have done I could not manage to solve the problem. Thanks for your contribution.
• Nov 1st 2009, 03:14 PM
skeeter
Quote:

Originally Posted by JohnDoe
Hello everyone,
I wonder if it is possible to graph |x|+|y|=x^2+y^2 function on TI89 Titanium if so can someone please provide me step-by-step instructions because I always get stuck with the "Undefined Variable" error. No matter what I have done I could not manage to solve the problem. Thanks for your contribution.

Module 13 - Implicit Differentiation
• Nov 2nd 2009, 05:23 AM
JohnDoe
Thanks for the reply but I did not understand what to do. On Wolfram Alpha when I enter the variables I can get the graph, but when I enter them in the same format on TI-89 Titanium I get the "Undefined Variable" error. How can I define the variable, which graph mode and which settings should I use? On the other hand when I use implict differentiation I get a graph that is not alike with the graph I get on Wolfram Alpha. I am very confused should TI89 not be able to graph such functions with ease?(BTW I am a high-school student and unfamiliar with implict differentiation)
• Nov 2nd 2009, 07:18 AM
Jameson
Quote:

Originally Posted by JohnDoe
Thanks for the reply but I did not understand what to do. On Wolfram Alpha when I enter the variables I can get the graph, but when I enter them in the same format on TI-89 Titanium I get the "Undefined Variable" error. How can I define the variable, which graph mode and which settings should I use? On the other hand when I use implict differentiation I get a graph that is not alike with the graph I get on Wolfram Alpha. I am very confused should TI89 not be able to graph such functions with ease?(BTW I am a high-school student and unfamiliar with implict differentiation)

You need to read the link provided and follow the instructions. They will help you and you don't need to know anything about calculus to do this. Basically what you are going to do is graph this 3-d equation and then only view the xy-plane, which will show you what you are looking for.
• Nov 2nd 2009, 12:03 PM
JohnDoe
I have managed to graph the sample function on the link but I am still unable to graph |x|+|y|=x^2-y^2 any suggestions? When I try to graph it the only thing I see is x axis and y axis
• Nov 2nd 2009, 03:06 PM
Jameson
Quote:

Originally Posted by JohnDoe
I have managed to graph the sample function on the link but I am still unable to graph |x|+|y|=x^2-y^2 any suggestions? When I try to graph it the only thing I see is x axis and y axis

What do you have set for you x and y min/max values?
• Nov 2nd 2009, 03:46 PM
skeeter
screenshots ... note that the graph is in a small window.
• Nov 3rd 2009, 11:17 AM
JohnDoe
I have finally managed to graph the equation my mistake was to write the equation z=x^2-y^2=|x|+|y|
• Nov 29th 2009, 06:57 AM
Bill Zimmerly
Quote:

Originally Posted by skeeter
screenshots ... note that the graph is in a small window.

I just love replies with associated screenshots! (Wink)