Re: General--Differential equation problem..

*To*: mathgroup at smc.vnet.net*Subject*: [mg66353] Re: General--Differential equation problem..*From*: Heinz Spindler <heinz at mathematik.Uni-Osnabrueck.DE>*Date*: Wed, 10 May 2006 06:34:26 -0400 (EDT)*Organization*: Universitaet Hannover*References*: <e3jttb$94n$1@smc.vnet.net>*Reply-to*: Heinz.Spindler at mathematik.Uni-Osnabrueck.DE*Sender*: owner-wri-mathgroup at wolfram.com

randomtalk at gmail.com wrote: >hello, i was trying to solve a set of differential equations needed for a school project.. However, i'm completely new to mathematica 5.0, and i have downloaded trial, here is what i inputed into the software: > >In[2]:= >DSolve[{x'[s] == Cos[z], y'[s] == Sin[z], z'[s] == 1/r, r == 2}, {x, y, z}, s] > >returns this error: DSolve::dvnoarg: The function z appears with no arguments. > >Is there anything wrong with what i inputed? The differential equations came from this website: http://fy.chalmers.se/LISEBERG/eng/loop_pe.html > >Link to the forum page for this post: >http://www.mathematica-users.org/webMathematica/wiki/wiki.jsp?pageName=Special:Forum_ViewTopic&pid=10212#p10212 >Posted through http://www.mathematica-users.org [[postId=10212]] > > >Try this: > DSolve[{x'[s]==Cos[z[s]],y'[s]==]Sin[z[s]],z'[s]==1/2},{x[s], y[s],z[s]},s]