Re: Troubles with Integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg70238] Re: Troubles with Integrate
- From: Roland Franzius <roland.franzius at uos.de>
- Date: Sun, 8 Oct 2006 02:05:07 -0400 (EDT)
- Organization: Universitaet Hannover
- References: <eg84hk$nir$1@smc.vnet.net>
Roman V. Kiseliov schrieb:
> If I try to do following calculation Mathematica 5.2.0.0 can't evaluate
> integrals.
>
> psi:= (-Pi^(-1))*((Sin[Pi*((t - 5/4)/3)]/(t - 5/4))*Cos[Pi*(t - 5/4)] +
> (Sin[Pi*(t + 1/4)]/(t + 1/4))*Cos[Pi*(t + 1/4)]) +
> (1/Pi)*((Sin[2*Pi*((t - 7/8)/3)]/(t - 7/8))*Sin[2*Pi*(t - 7/8)] -
> (Sin[2*Pi*((t - 1/8)/3)]/(t - 1/8))*Sin[2*Pi*(t - 1/8)]);
>
> Integrate[psi*psi, t]
> Integrate[psi*psi, {t, -inf, +inf}]
This is an easy one if conviently represented. Try
phi=psi^2//TrigToExp//ExpandAll
Now its of course art to pass to the limit t->+-Infinity
--
Roland Franzius