Re: Sin[30*Degree] vs Sin[29*Degree]

*To*: mathgroup at smc.vnet.net*Subject*: [mg72090] Re: Sin[30*Degree] vs Sin[29*Degree]*From*: Heiko Damerau <heiko.damerau.news at cern.ch>*Date*: Mon, 11 Dec 2006 04:55:26 -0500 (EST)*Organization*: CERN News*References*: <elglnb$h7f$1@smc.vnet.net>

Dear Steven, The behaviour of Mathematica is perfectly consistent. It depends on whether you look for an exact or for a numerical result. Sin[30*Degree] is indeed 1/2 and this result is exact. However, for Sin[29*Degree] or Sin[31*Degree] Mathematica cannot find any exact solution and just keeps the expression unevaluated. If you want the numerical result, ask e.g. for N[Sin[29*Degree]]. By typing Sin[29*Pi/180.] you are asking for the numerical result as 180. <- with a dot at the end means the numerical value 180 and Mathematica will automatically perform a numerical calculation. Try to ask Mathematica for the exact result of Sin[29*Pi/180] and you will see that the expression is kept as well as Sin[29*Degree]. Again, this time Mathematica tries to find the exact solution... which doesn't exist. Hope this helps, Heiko Steven Shippee schrieb: > What is happening here: > > Sin[30*Degree] > Sin[31*Degree] > Sin[29*Degree] > which makes it appear that only the first line of input works? > > However, if I do something like: > > \!\(Sin[\(29*Pi\)\/180. ]\) > > I get the expected result ... I'm sure it is me, what am I missing in that I > think I am not seeing consistent behavior? > > Thanks in advance, > > Steven Shippee > > slshippee at comcast.net > > > >