Re: Laplace Transform

*To*: mathgroup at smc.vnet.net*Subject*: [mg65188] Re: Laplace Transform*From*: Marlies.Goorden at physics.unige.ch*Date*: Fri, 17 Mar 2006 00:13:31 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Thank your for the replies. Generating conditions indeed helps. What I still don't understand is the following. I can generate conditions in three ways which I think are equivalent: LaplaceTransform[Sin[a t], t, s, GenerateConditions -> True, Assumptions -> NotElement[a, Reals]] LaplaceTransform[Sin[a t], t, s, GenerateConditions -> True, Assumptions -> Element[a, Complexes]] LaplaceTransform[Sin[a*t], t, s, GenerateConditions -> True, Assumptions -> Im[a] > 0] The second one doesn't work (this was what I was doing before already). Can anyone tell me what the difference is? And why do I have to generate these conditions, shouldn't mathematica anyway assume that a is complex? Or should I always put in these assumtpiosn when I do a laplace transform. Thank you for your help, Marlies