Re: simplify a trig expression
- To: mathgroup at smc.vnet.net
- Subject: [mg65432] Re: simplify a trig expression
- From: Roland Franzius <roland.franzius at uos.de>
- Date: Sat, 1 Apr 2006 05:38:50 -0500 (EST)
- Organization: Universitaet Hannover
- References: <e0j3a1$foe$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Murray Eisenberg schrieb: > A direct substitution (with paper and pencil) gives that the integral of > Cos[x]/(Sin[x] + 1) is Log[Sin[x] + 1]. This is valid provided Sin[x] > is not -1. > > Mathematica gives: > > Integrate[Cos[x]/(Sin[x] + 1), x] > 2 Log[Cos[x/2] + Sin[x/2]] > > Is there some simple way to coerce the latter Mathematica-supplied > result into the paper-and-pencil answer? In[] Integrate[Cos[x]/(Sin[x] + 1), x] // Times[#, 1/2] & // Map[Power[#, 2] &, #] & // FullSimplify Out[] Log[1 + Sin[x]] -- Roland Franzius