Re: Complex Numbers
- To: mathgroup at smc.vnet.net
- Subject: [mg47435] Re: Complex Numbers
- From: bobhanlon at aol.com (Bob Hanlon)
- Date: Mon, 12 Apr 2004 03:44:50 -0400 (EDT)
- References: <c5b0tc$7lc$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Simplify[Re[Exp[a I] Exp[b I]], Im[a]==0 && Im[b]==0] Cos[a + b] Also look at the standard add-on package Algebra`ReIm` Bob Hanlon In article <c5b0tc$7lc$1 at smc.vnet.net>, Alejandro Vizcarra <gebankos at prodigy.net.mx> wrote: << I always have problems when dealing with complex numbers. How can i work with Mathematica in such a way that every expression will be considered real unless it is declared explicitly complex (like a = 3 + 4 I ) ? For example if I type Re[ComplexExpand[ Exp[a I] Exp[b I]]] I get the answer -Im[Sin[ a+b]]+Re[Cos[a+b]] Instead of simply Cos[a+ b]