Re: integrat trig radical
- To: mathgroup at smc.vnet.net
- Subject: [mg39581] Re: integrat trig radical
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Tue, 25 Feb 2003 02:54:56 -0500 (EST)
- Organization: Universitaet Leipzig
- References: <b3ck48$7vs$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
may be that
Plot3D[
Evaluate[Re[Cos[z/2] /. z -> x + I y]], {x, -2Pi, 2Pi}, {y, -2Pi,
2Pi}]
and
Plot3D[
Evaluate[Re[Sqrt[(1 + Cos[z])/2] /. z -> x + I y]], {x, -2Pi,
2Pi}, {y, -2Pi, 2Pi}]
are not the same ?
Regards
Jens
Friedrich Laher wrote:
>
> is there any mathematical reason for mathematica, not 1st internally
> using
> Cos[x/2] = Sqrt[(1 + Cos[x])/2]
> before
> integrating Sqrt[1 + Cos[x]] ?
> It
> even refuses to answer True
> to
> Integrate[Sqrt[1 + Cos[x]],x] == 2*Sqrt[2]*Sin[x/2]
> F.