Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2012

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: How Expand?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg127834] Re: How Expand?
  • From: daniel.lichtblau0 at gmail.com
  • Date: Sat, 25 Aug 2012 04:27:01 -0400 (EDT)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • Delivered-to: l-mathgroup@wolfram.com
  • Delivered-to: mathgroup-newout@smc.vnet.net
  • Delivered-to: mathgroup-newsend@smc.vnet.net
  • References: <k17g9n$dre$1@smc.vnet.net>

On Friday, August 24, 2012 4:08:07 AM UTC-5, news wrote:
> Hi folks,
> 
> 
> 
> How can I expand the following :
> 
> 
> 
> [ 1 + cos(x) + i sin(x) ]^3
> 
> 
> 
> to obtain;
> 
> 
> 
> 8 cos(x/2)^3 [cos(3x/2)+ i sin(3x/2)]
> 
> 
> 
> Thanks a lot.
> 
> 
> 
> Max.

This will come pretty close.

In[6]:= ee = 1+Cos[x]+I*Sin[x];

In[7]:= InputForm[TrigFactor[TrigExpand[ee]]]

Out[7]//InputForm= Cos[x/2]*(2*Cos[x/2] + (2*I)*Sin[x/2])

Daniel Lichtblau
Wolfram Research



  • Prev by Date: ContourPlot non rectangular evaluation?
  • Next by Date: Re: Group and Replace itens sequence in a list
  • Previous by thread: Re: How Expand?
  • Next by thread: Re: How Expand?