On Tue, 29 Nov 2011 13:14:36 -0700 jrodri1...@gmail.com wrote: > Hi! I'm working with an expression involving imaginary exponentials > and their conjugates: > > exp(i•k•x) > > exp(i•k•x)*=exp(-i•k•x) > > However, when multiplying them together, I do not get the arguments > to evaluate to zero. My variables x and k are real, and I've told > sage to assume that they are real. But it will not evaluate: > > exp(i•k•x)•(exp(i•k•x))* > > as: > > exp(i•k•x+(i•k•x)*)=exp(i•k•x+(i*•k*•x*))=exp(i•k•x+(-i•k•x))=exp(i•k•x-i•k•x)=exp(0)=1. > > > Any ideas?
Try this: sage: var('x',domain=RR) x sage: var('k',domain=RR) k sage: exp(i*x*k) e^(I*k*x) sage: exp(i*x*k)*exp(-i*x*k) 1 The assume() system is from maxima. Unfortunately, basic arithmetic with symbolic expressions doesn't know about these. It uses a different system as you can see. There must be a ticket to make these two assumption systems play nice, but I can't find it ATM. Cheers, Burcin -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org