Re: Integration program

To: CALC-TI@LISTS.PPP.TI.COM
Subject: Re: Integration program
From: Dave Slomer <slomerda@UCRWCU.RWC.UC.EDU>
Date: Sun, 19 Dec 1999 19:05:12 -0500
References: <0.8d22361c.258e99f2@aol.com>
Reply-To: Dave Slomer <slomerda@UCRWCU.RWC.UC.EDU>

----- Original Message -----
From: Ricardo Navarro <Fb4459@AOL.COM>
Subject: Re: Integration program

> Thanks for the sad info....I guess it was too good to be true! So can the
> TI-92/89 really handle (indefinite) symbolic integration? or just some
> special (simple) cases??

It can handle just about ANY integral, though in a way they're ALL special
cases of a finite list of known integrals.

> btw, the guy who told me about this page said that "The Integrator" was
> written in JAVA, so it must be some kind of remote file located on the
> server, not a little JAVA applet as I may have mistakenly mentioned...

NOT Java. And definitely not little! Some humongous C program on a mainframe
at Wolfram, probably (address below?).

> address is:  http://integrals.wolfram.com/index.cgi (and it CAN integrate
> f(x)=(4+x^3)^cos x)

Yes, the "integrator" on that page sure did. The answer contains a reference
to a function called HYPERGEOMETRIC2F1. Derive has a file that can be loaded
to augment its power (named HYPERGEO.MTH) But, even after loading that file,
Derive still did not give the result that Wolfram's "integrator" did.

Wolfram are the Mathematica guys, and I guess we just learned that maybe it
does more than Derive (and therefore your 89 or 92), BUT MAYBE it's more of
a contrived example for that page.

Anybody use Mathematica? Try to just integrate (4+x^3)^cos x with respect to
x and see what you get.

In fact, HERE is what Wolfram's "integrator" gives:

(x^2*(4 + x^3)^cos*Hypergeometric2F1[2/3, -cos, 5/3, -x^3/4])/ (2*(1 +
x^3/4)^cos)

and I don't know how to interpret that, since (a) I don't know how Wolfram
implemented HYPERGEOMETRIC2F1 and (b) I have no idea what it is, anyway!!

Dave Slomer
Greenhills, OH
davidslomer@geocities.com
http://www.geocities.com/CapeCanaveral/Lab/8692/

******************************************************************
* To UNSUBSCRIBE, send an email TO: listserv@lists.ppp.ti.com
* with a message (not the subject) that reads SIGNOFF CALC-TI
*
* Archives at http://peach.ease.lsoft.com/archives/calc-ti.html
******************************************************************

References:

Re: Integration program

From: Ricardo Navarro <Fb4459@AOL.COM>