Deriviation d/dt(x(t))

*To*: mathgroup at smc.vnet.net*Subject*: [mg27407] Deriviation d/dt(x(t))*From*: "Christian Maier" <maier1 at sbox.tu-graz.ac.at>*Date*: Sun, 25 Feb 2001 00:53:30 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

I have a problem, having a definition of a circle: x^2+y^2=r^2 Where x and y are functions of the time: x(t), y(t) and r ist a constant. Now I want to deriviate the equation to get the velocity vector. It should be : 2 x dx/dt +2 y dy/dt = 0 Can anyone tell me how to do? Thans in advance! Christian Maier