polar coordinates

*To*: mathgroup at smc.vnet.net*Subject*: [mg13397] polar coordinates*From*: "Toshiyuki Meshii" <tm60 at cornell.edu>*Date*: Thu, 23 Jul 1998 03:32:40 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Dear Sirs, Let me know the way to work with patial differentiation on polar coordinates. For examples, when x = r Cos[q] and y = r Sin[q] how can you obtain du[x,y]/dx = Cos[q] * (du[x,y]/dr) - Sin[q] / r * (du[x,y]/dq) by Mathematica? Thank you in advance. Toshiyuki