Date: Apr 1, 2012 3:43 AM
Author: David Reiss
Subject: Re: simplify Arg[E^(I x)]?

For a given value of x, Arg[Exp[I x]] is not necessarily equal to x:

Plot[Arg[Exp[I x]], {x, 0, 4 Pi}]

So, to get the answer you want, you need to restrict x as in:

FullSimplify[Arg[E^(I x)], {x > -\[Pi], x <= \[Pi]}]

--David


On Mar 31, 4:42 am, Neal Becker <ndbeck...@gmail.com> wrote:
> Why doesn't this simplify?
>
> Fullsimplify[Arg[E^(I x)], x \[Element] Reals]
>
> I expect to get 'x'.
>
> Is there some way I can get this to simplify?