Date: Apr 4, 2008 6:37 PM
Author: Wouter Geelen
Subject: Re: Solving equation

roberson@ibd.nrc-cnrc.gc.ca (Walter Roberson) wrote in 
message <ft694d$5ki$1@canopus.cc.umanitoba.ca>...
> In article <ft67km$agj$1@fred.mathworks.com>,
> Wouter Geelen <wouser_geelen@hotmail.com> wrote:
>

> >I tried to do this myself but I can't get it done. I got
> >the following equation.

>
> >Ti = -1200*exp(-1/7200*t)+1200
>
> >Now I want to solve this function for Ti = 1080. So what
I
> >want to find is t. How do I do that :?
>
> Ti = -1200*exp(-1/7200*t)+1200, so
> Ti - 1200 = -1200 * exp(-t/7200), so
> (1200 - Ti)/1200 = exp(-t/7200), so
> ln((1200 - Ti)/1200) = -t/7200, so
> -ln(1200/(1200-Ti)) = -t/7200, so
> t = 7200 * ln(1200/(1200-Ti))
>
> Substituting in Ti = 1080, we get the result 7200 * ln(10)
> which is about 16578.61267.
>
> --
> "Is there any thing whereof it may be said, See, this

is new? It hath
> been already of old time, which was before us." --
Ecclesiastes

Hahahaha yeah I know it can be done by algabra I already
did myself lol but how do I this in matlab? Ain't there a
function solve equation for paramater x?!? Or something
like maple has?