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Re: Taking the Arg of a complex number

• To: mathgroup at smc.vnet.net
• Subject: [mg122084] Re: Taking the Arg of a complex number
• From: Jacopo Bertolotti <jacopo.bertolotti at gmail.com>
• Date: Thu, 13 Oct 2011 03:46:48 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201110120744.DAA16295@smc.vnet.net>

 From the Help page for Arg:
* Arg[z] is left unevaluated if z is not a numeric quantity.
Therefore what you get is exactly the expected behaviour but I admit 
that right now I do not know how to extract the argument of a complex 
number symbolically (I would try a pattern matching but I can not make 
aworking example for you right now).

Regards

Jacopo

On 10/12/2011 09:44 AM, Ben wrote:
> Would appreciate any help here, endless Googling has not revealed the answer to me:
>
> If I define a complex number symbolically, such as x = A Exp[I phi], why does Arg[x] never return the answer I expect, phi? Using Refine with the as sumptions phi is real and between 0 and 2 pi, and that A is greater than 0 doesn't seem to help. All I get is Arg[Exp[I phi]]
>
>

• References:
  • Taking the Arg of a complex number
    • From: Ben <bjgear@googlemail.com>