Re: Derivative of g(z) = Arg(z) and f(z) = Re(z) + Im(z)?

*To*: mathgroup at smc.vnet.net*Subject*: [mg54136] Re: Derivative of g(z) = Arg(z) and f(z) = Re(z) + Im(z)?*From*: highegg at centrum.cz (highegg)*Date*: Fri, 11 Feb 2005 03:34:06 -0500 (EST)*References*: <xglsxn7ymm4h@legacy>*Sender*: owner-wri-mathgroup at wolfram.com

On 9 Feb 05 13:59:53 -0500 (EST), Marie wrote: >How do I solve a derivative of a complex function Arg(z) or Re(z) + >Im(z) by definition? (f(z) - f(w))/(z-w) -> f'(w) as z->w... hello, function like Re(z)+Im(z) or Arg(z) do not have a complex derivative (we say they're non-holomorphic), because they don't satisfy the Cauchy-Riemann conditions. http://mathworld.wolfram.com/Cauchy-RiemannEquations.html