hey all!

 

I currently use GraphCalc v4.0.1

It supports 3D graphing, and is a pretty interesting program, however I was wondering if there are any graphing programs that support relational graphs? I find having to create graphs as functions only a bit restrictive.

 

an example is z^2 = x^2 + y^2 (a sphere)

I can't make one with my current graphing calc because it doesnt do non-function graphing.

 

If anyone knows of a graphing calculator that can do what I'm proposing, please post a link. BTW - It'd have to be a free one too lol

 

Thanks in Advance!

hey all!

 

I currently use GraphCalc v4.0.1

It supports 3D graphing' date=' and is a pretty interesting program, however I was wondering if there are any graphing programs that support relational graphs? I find having to create graphs as functions only a bit restrictive.

 

an example is z^2 = x^2 + y^2 (a sphere)

I can't make one with my current graphing calc because it doesnt do non-function graphing.

 

If anyone knows of a graphing calculator that can do what I'm proposing, please post a link. BTW - It'd have to be a free one too lol

 

Thanks in Advance![/quote']

 

 

Well, usually in these situations you can solve for a value in order to get a function... in the example you gave, for instance:

 

[math]z^2 = x^2 + y^2[/math]

[math]z = \pm \sqrt{x^2 + y^2}[/math]

 

You then split this into two functions to get the complete graph:

 

[math]z_{1}(x,y) = + \sqrt{x^2 + y^2}[/math]

[math]z_{2}(x,y) = - \sqrt{x^2 + y^2}[/math]

 

 

The Texas instrument line of graphing calculators is one of the best in my opinion. The Ti-89s are pretty good.

When I do that I get a wierd looking oval shape on my graphcalc. And btw I'm talking about 3d graphing calculators for PC.

 

Looks like this:

 

 

with the equations at the top right corner. As you can see, its not close to a sphere lol, more like to huge sails billowing out from the origin in opposite directions.

 

And what if I wanted to make 3D equations that you can't isolate z, x, or y? There some of the more interesting looking ones too lol...

 

(side note - why won't my graph show with the IMG tags? )

The Texas instrument line of graphing calculators is one of the best in my opinion. The Ti-89s are pretty good.

i'm the only one in my school that has a 89 titanium. they found out that it can do derivatives and integral and such and now they all want one.

 

it kinda screwed me over though. i had a test and one section was about the kepler's laws. i couldn't find the third root key. two seconds after i turned in the test i almost hit myself because i was too stupid to just raise it to the 1/3 power....

i'm the only one in my school that has a 89 titanium. they found out that it can do derivatives and integral and such and now they all want one.

 

it kinda screwed me over though. i had a test and one section was about the kepler's laws. i couldn't find the third root key. two seconds after i turned in the test i almost hit myself because i was too stupid to just raise it to the 1/3 power....

 

Yea, I too was the only one with a TI-89... and I loved that it did Limits and Derivatives and Intrigals... but it didn't have a nth root key... and it actually took me a couple days to figure out to raise to the 1/n power for then nth root...