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Re: How to use Mathematica find the solution of an
Posted:
May 27, 2013 4:20 AM


Many thanks for the reply.
If we consider
1/((I w)(1+I w)^2)
we have
angle(I w)2*angle(1+I w) = 180
902*angle(1+ I w)=180
2*angle(1+i w)=90 angle(1+iw)=45
therefore w = 1
and 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 thanks
Ed
On 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. >> >>



