Re: Request for Assistance on Logs/Anti-LOGS

To: CALC-TI@LISTS.PPP.TI.COM
Subject: Re: Request for Assistance on Logs/Anti-LOGS
From: Dave Slomer <slomerda@UCRWCU.RWC.UC.EDU>
Date: Fri, 17 Dec 1999 17:58:56 -0500
Comments: To: "Roger D. Cravens, Jr." <morris_e@MINDSPRING.COM>
References: <4.2.0.58.19991217123723.0098d6b0@pop.mindspring.com>
Reply-To: Dave Slomer <slomerda@UCRWCU.RWC.UC.EDU>

> Anyone know how to do anti-LOGs on the TI-89.  I went to the
> "Catalog" and located the LOG function, but after an hour
> of playing around I still couldn't seem to get it.  I'm working
> on some electronics calculations and they need the anti-log
> function which is not included with the TI-89.  I assume a -1
> somewhere would do it, but I haven't cracked the code yet.

"anti"logs would be more appropriately called "inverse"logs.

Given x, one finds log x from the y-coordinate on the graph of y=log x (or a
table).
Given log x (the *Y* coordinate), one finds x from the same graph, but by
working "backwards" (hence the name "antilog") from y on the graph down to x
on the x-axis.

Since y=log x and x=10^y are different representations of the SAME functions
(using the definition of log) and
since x=10^y and y=10^x are INVERSE functions,
then y=log x and y=10^x are inverses of each other,
so antilog(x)=10^x

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:

Request for Assistance on Logs/Anti-LOGS

From: "Roger D. Cravens, Jr." <morris_e@MINDSPRING.COM>

Prev: Request for Assistance on Logs/Anti-LOGS
Next: Re: Request for Assistance on Logs/Anti-LOGS
Index(es):
- Main
- Thread