Re: Very urgent problem...PLEASE help me!

*To*: mathgroup at smc.vnet.net*Subject*: [mg32869] Re: [mg32855] Very urgent problem...PLEASE help me!*From*: Tomas Garza <tgarza01 at prodigy.net.mx>*Date*: Sat, 16 Feb 2002 04:35:28 -0500 (EST)*References*: <200202150750.CAA09948@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I usually try to stay out of homework problems, so I hope this is not the case with you. The solution to your system is straightforward. Try this: In[11]:= sol = Solve[eqn, {y1[t], y2[t], y3[t], y4[t]}] A longish expression appears in terms of Sin[w t}, Cos[w t] and Csc[w t], but you also have this strange Y0[2 w t] inside. The value of Y3[t] is sol[[1, 3, 2]], which you may now plot (substitute z = w t and plot between z = 0 and z = 4 Pi) making Y0[2 w t] = some constant, e.g. 1. You may also use Simplify to get a slightly simpler expression. The plot is rather ugly, with a lot of singularities. I hope I'm interpreting your problem correctly. Tomas Garza Mexico City ----- Original Message ----- From: "Detlef Mueller" <Detlef.Mueller at fh-ge.de> To: mathgroup at smc.vnet.net Subject: [mg32869] [mg32855] Very urgent problem...PLEASE help me! > Hi out there! > > I'm a student working on a test with Mathematica...and I've got > massive problems with this task here: > > http://home.t-online.de/home/harrytasker/Task.nb > > If it's not working, here's a scan of it > > http://home.t-online.de/home/harrytasker/scan6.JPG > > (Sorry it's in german..anyhow, it is obviously a system of equations. > I just have to plot the solution of y3(t) in the limits of 0<=w t<=4 > Pi). > > But how do I do it? > It shouldn't be that much work...but I don't get the idea HOW. > I tried with LinearSolve...but out comes a (very complicated) result, > which I'm not able to plot somehow. > Also, there's this Y0-thing..nothing is specified about this, should I > just take it as a constant (because Plot requests a numerical value!). > > So, you see, I'm rather confused...please help me! > > THANKS A LOT IN ADVANCE! > > Bye > Detlef Mueller > > P.S.:I'm using Mathematica 3.0 on PC...if it's important. >

**References**:**Very urgent problem...PLEASE help me!***From:*Detlef.Mueller@fh-ge.de (Detlef Mueller)