Re: Equation problem
- To: mathgroup at smc.vnet.net
- Subject: [mg42214] Re: [mg42206] Equation problem
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Tue, 24 Jun 2003 01:27:00 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Monday, June 23, 2003, at 06:49 PM, Dan wrote:
> I need to solve the system of equations (in Mathematica notation):
>
> r1 == 0.0298
> r2 == 0.0335
> n == Abs[(r2-r1)/T]
> 2*Pi*Sum[r1+i*T, {i,0,n}] == 10
> T>0
>
> I tried (ignoring T>0) to use NSolve, which didn't work. I guessed the
> problem is that the summation limit depends on T which is also a part
> of the
> summand. However, Mathematica succefully solves the simpler Sum[n, {i,
> 0,
> n}] == 2. What is the essence of the problem? How can I solve it?
>
>
The problem seems to be you your confusing Equal (==) with Set (=).
r1 = 0.0298;
r2 = 0.0335;
n = (r2-r1)/T;
Solve[2*Pi*Sum[r1+i*T,{i,0,n}]==10,T]
Out[11]=
{{T->0.0000750721}}
Andrzej Kozlowski
Yokohama, Japan
http://www.mimuw.edu.pl/~akoz/
http://platon.c.u-tokyo.ac.jp/andrzej/