```Date: May 27, 2013 4:20 AM
Author: emammendes@gmail.com
Subject: Re: How to use Mathematica find the solution of an

Many thanks for the reply.If we consider1/((I w)(1+I w)^2)we have-angle(I w)-2*angle(1+I w) = -180-90-2*angle(1+ I w)=-180-2*angle(1+i w)=-90angle(1+iw)=45therefore w = 1and probably something similar for w=-1.I feel that I do not know how Mathematica deals with the argument of a complex number. To be honest I would like to know what is going on under the hood of PhaseMargins.Many thanksEdOn May 24, 2013, at 7:23 AM, Bob Hanlon <hanlonr357@gmail.com> wrote:>> The equation does not appear to have a solution except as a limit (from> below) but then the solution is either -1 or 1.>>> eqn = Arg[-(I/((1 + I w)^2 w))] == -Pi;>>> eqn // Simplify>>> False>>> eqn /. {{w -> -1}, {w -> 1}}>>> {False, False}>>> Limit[Arg[-(I/((1 + I w)^2 w))],>  w -> -1, Direction -> 1] == -Pi>>> True>>> Limit[Arg[-(I/((1 + I w)^2 w))],>  w -> 1, Direction -> 1] == -Pi>>> True>>>> Bob Hanlon>>>>> On Thu, May 23, 2013 at 4:04 AM, Eduardo M. A. M. Mendes <> emammendes@gmail.com> wrote:>>> Hello>>>> I need to solve the following equation:>>>> Arg[-(I/((1+I \[Omega])^2 \[Omega]))]==-\[Pi]>>>> I have tried Solve (empty output), Reduce (it gives some results but not>> the answer Omega=1) and FindRoot (it gives Omega=1 but it is a>> numerical search).   Is there a way to get the solution not using a>> numerical search?>>>> Many thanks>>>> Ed>>>> PS.   I need to solve several equation of the same kind.>>>>
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