Re: kernel problem for trigonometry

*To*: mathgroup at smc.vnet.net*Subject*: [mg29850] Re: kernel problem for trigonometry*From*: "Orestis Vantzos" <atelesforos at hotmail.com>*Date*: Fri, 13 Jul 2001 04:19:30 -0400 (EDT)*Organization*: National Technical University of Athens, Greece*References*: <9ijhqn$rhr$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Well, the trig expression does not evaluate to anything by itself, unless you use N to turn it into a real number. By calling FullSimplify you tell Mathematica to apply trig identities in an effort to simplify the expr. It is obvious that simple arguments like Pi, 2 Pi, Pi/2, Pi/3 etc. simplify immedaitely to algebraic expressions involving simple roots. Not so classical arguments like 220deg do not map readily to algebraic expr. of roots. It is obvious that there is a wide range of possible transformation that could be applied, so it is only natural that FullSimplify takes a lot of time to navigate through the mess of trig identiies. Orestis "Soh Pek Hooi" <fbasohph at nus.edu.sg> wrote in message news:9ijhqn$rhr$1 at smc.vnet.net... > Hi, > > May I find out the reason for the Kernel to compute the following with > longer than the normal response time? It take several minutes to return a > value, especially when the degree is not one of 0, 30, 45, 90 Degrees, and > so on. > > FullSimplify[Sin[110 Degree]/Cos[220Degree]] > > Will appreciate your reply. > > Pek >