diff(integrate(cos(k*x)*cos(n*x),x));



I guess that maxima doesn't have the commercial maxima's trigcontract.
Dan Stanger

wang yin wrote:

> I got this result using trigsimp.
> But I don't know how to get cos(k*x)*cos(n*x).
> Can anyone tell me?
>
> (C22) TRIGSIMP(DIFF(INTEGRATE(COS(k*x)*COS(n*x),x),x));
>
>                         COS((n + k) x) + COS((n - k) x)
> (D22)                   -------------------------------
>                                        2
>
> On Mon, Jan 13, 2003 at 07:00:44PM +0100, Khiraly Kalman wrote:
> > Hi!
> > diff(integrate(cos(k*x)*cos(n*x),x));
> >
> > Why doesn't done the same resultat?:
> > Theoretically diff(integrate(f(x)))=f(x)
> >
> > But maxima doesn't.
> >
> >  diff(integrate(cos(k*x)*cos(n*x),x))=cos(k*x)*cos(n*x)
> >
> > Thanks
> >
> >
> > _______________________________________________
> > Maxima mailing list
> > Maxima@www.math.utexas.edu
> > http://www.math.utexas.edu/mailman/listinfo/maxima
>
> --
> Wang Yin
> DA Lab, Tsinghua University,
> 100084
> Beijing China
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