Batman Equation

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Rex Boggs

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Nov 3, 2011, 10:51:00 PM11/3/11
to tinspire
Check out
http://www.gizmodo.com.au/2011/07/the-batman-equation/
and
http://math.stackexchange.com/questions/54506/is-this-batman-equation-for-real

Anyone care to put the equations into a tinspire? Might be a good job for a keen student.

Lots of maths in this.

Cheers

Rex

Nelson Sousa

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Nov 4, 2011, 4:04:34 AM11/4/11
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That's an implicit equation, that the Nspire does not support.

It needs to ben either solved for y (which doesn't seem easy if at all possible) or parametrized which can also be quite hard.

The Voyage 200 and TI-89 do implicit equations but this one may be painfully slow to plot.

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Nelson Sousa

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Jim Fullerenex

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Nov 4, 2011, 4:45:27 AM11/4/11
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Are you sure, Nelson? :)

To tell the truth, I find myself quite crazy on even attempting to start. And I have always kept in mind (from my previous experiences) that Nspire is very unhappy with abs(). The absolute values always stir things up, introducing the notorious sign() in possibly a total mess, which I personally dislike a lot.

Warning: never ever copy that hell long batman equation into the graphing page directly!!! 

Observing that the equation actually consists of six parts multiplied to zero, I try to draw the parts separately.

Attached screenshot:
1. defining individual terms
2. graph, do some modification, reset color and done!

Best,
Jim



2011/11/4 Nelson Sousa <nso...@gmail.com>
defining_individual_terms.jpg
Done_batman_logo.jpg

Jim Fullerenex

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Nov 4, 2011, 5:23:51 AM11/4/11
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Hi,

Half an hour. I packed the messy functions and expressions into a document with detailed explanation. (and a better batman logo :) )

Hope you like it!!!

Best,
Jim



2011/11/4 Jim Fullerenex <smoa...@gmail.com>
Batman equation.tns

Jim Fullerenex

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Nov 4, 2011, 5:27:35 AM11/4/11
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Add: screen shots for those who'd like a quick view.
Also I want to thank Rex for this great (and interesting) idea.

Cheers,
batman_equation_firstpage.jpg
improved logo.jpg

Nelson Sousa

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Nov 4, 2011, 7:43:32 AM11/4/11
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nicely done!!

Jim Fullerenex

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Nov 4, 2011, 8:59:09 AM11/4/11
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Yeah... :D  sometimes Nspire can be more powerful than the manual claims.

Cheers,

Rex Boggs

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Nov 4, 2011, 9:43:32 AM11/4/11
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Great work, Jim!
 
If folks want to find out how these equations actually generate the graphs, go to
and scroll down.   One chap explains which “factors” (actually equations) are responsible for each section of the graph.
 
There is a lot of good math in all of this, worth exploring.
 
Cheers
 
Rex
Jim



2011/11/4 Jim Fullerenex <smoa...@gmail.com>

Best,
Jim



2011/11/4 Jim Fullerenex <smoa...@gmail.com>

Best,
Jim



2011/11/4 Nelson Sousa <nso...@gmail.com>
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Jim Fullerenex

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Nov 4, 2011, 9:58:46 AM11/4/11
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Yep... The six parts are split and shown separately in "Batman equation.tns" Page 1.4 (though the final effect is a complete logo). Those who want to explore how different parts work can simply press "tab" and view function f1 to f6.

Best,
Jim



2011/11/4 Rex Boggs <rexb...@optusnet.com.au>

Jim Fullerenex

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Nov 4, 2011, 10:04:04 PM11/4/11
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One more implicit graph: the Love equation. 
Just to give another cool example.

Btw, Nelson, I never know TI-89 can do implicit graphing. My friend shows me the graph-type menu on TI-89 titanium, which seems to include only the following: "1. Function; 2. Parametric; 3. Polar; 4. Sequence; 5. 3D; 6. Diff Equations" 
All of these are included in Nspire OS 3.x. Have I missed anything?
Love equation.tns
Love equation.jpg
11-05-2011 Image001.jpg

John Hanna

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Nov 4, 2011, 10:35:36 PM11/4/11
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When you choose 3D on the TI-89 you can change the type from surface to contour to implicit, but I forget how!

 

     John Hanna

     jeh...@optonline.net

     www.johnhanna.us

     T3 - Teachers Teaching with Technology

     "A cowchip is paradise to a fly."

 


Travis Bower

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Nov 4, 2011, 11:08:16 PM11/4/11
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CAS only, right?

Sean Bird

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Nov 5, 2011, 12:26:31 PM11/5/11
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zeros(expression, var) or specifically
zeros((x^2+y^2-1)^3-x^2*y^3,y)  is a CAS function.

3D works exactly the same on any TI-Nspire.
Similar to the zeros command, you can graph in 3D with zmin=0 and you can what the graph looks like
So you could graph z1(x,y)=(x^2+y^2-1)^3-x^2*y^3
and with
xmin=-2, xmax=2
ymin=-2, ymax=2
zmin= 0, zmax=1
Then press z to view it from the x-y plane.

The other graph that Jim showed would be z2(x,y)=x^(2)+(y-root(x^(2),3))^(2)-1
Increase the ymax to about 3.
1heart.jpg
2hearts.jpg
Batman equation.tns

Travis Bower

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Nov 5, 2011, 2:40:17 PM11/5/11
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Thanks.
"Trying to find the z?" scroll down of course [it took me sec (=minutes) to figure it out; I'll save you the trouble.

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11-05-2011 Image007.jpg

Sean Bird

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Nov 5, 2011, 7:15:41 PM11/5/11
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I had meant to attach 'this' version of Batman equation tns. It has a portion that will work on the numeric TI-Nspire.

There are a couple of videos showing how to do this which perhaps can save on any frustration of not finding the z range.
http://www.youtube.com/watch?v=MUdn46lvTuY

Part2 is found at
http://www.youtube.com/watch?v=qgIv-hjIXDc

Enjoy,
Sean Bird
Indianapolis, IN
Batman equation w 3D.tns

Jim Fullerenex

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Nov 5, 2011, 11:17:30 PM11/5/11
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Hi Sean,

Your 3D-2D implicit grapher is even cooler!!! That's indeed a very clever way. Thanks for the idea.

Btw, the 3D batman equation looks awful; I see that term3 and term5 are not working at all; term4 gives only 4 dots. I've tried to change document settings but the problem persists. Anyone has a tip of thought? I guess the culprit is still the messy nest of absolute values.

Best,
Jim



2011/11/6 Sean Bird <covena...@gmail.com>

Nelson Sousa

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Nov 7, 2011, 3:52:24 AM11/7/11
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It's under Diamond+F on the 89 anv Voyage 200 if memory serves me
correctly. There you choose between wireframe, hidden surface,
implicit and contour.

Cheers,
Nelson

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