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Re: Solving equation
Posted:
Apr 4, 2008 6:12 PM


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/(1200Ti)) = t/7200, so t = 7200 * ln(1200/(1200Ti))
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



