Re: Wierdness with the laplacian
- To: mathgroup at smc.vnet.net
- Subject: [mg45142] Re: [mg45132] Wierdness with the laplacian
- From: "Ingolf Dahl" <ingolf.dahl at telia.com>
- Date: Thu, 18 Dec 2003 06:55:17 -0500 (EST)
- Reply-to: "Ingolf Dahl" <ingolf.dahl at telia.com>
- Sender: owner-wri-mathgroup at wolfram.com
If you apply Simplify to your result, it will look nicer. Csc[z] is the same as 1/Sin[z]. But that of course also Mathematica should know, and why it does not do this simplification in the first place I do not know. Ingolf Dahl citing Peter Jay Salzman <p at dirac.org>: > Hi all, > > When I do: > > <<Calculus`VectorAnalysis` > SetCoordinates[Spherical[r, theta, phi] > Laplacian[ Exp[r^2] ] > > Mathematica gives: > > 2 2 > r 2 r 4 > Csc[theta] (6 E r Sin[theta] + 4 E r Sin[theta]) > ------------------------------------------------------ > 2 > r > > Which is wrong since Exp[r^2] is not a function of theta or phi. > > > Why is Mathematica giving this result? > > Thanks! > Pete > >