What variables are in a function and displaying surds

*To*: mathgroup at smc.vnet.net*Subject*: [mg31117] What variables are in a function and displaying surds*From*: michael_r_went at yahoo.com (Wonko the Sane)*Date*: Wed, 10 Oct 2001 19:14:36 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, Is there a way in Mathematica to generate a list of variables in an expression like Variable[]. For example if I passed the expression Sin[x+y]+ z/p - t the list {x,y,z,p,t} would be generated. Another unrelated question is when I use Mathematica V4.0 to calculate tables of ThreeJSymbols the outputs Generally consist of fractions of roots of the form Sqrt[a/b] , c/Sqrt[d] and Sometimes Sqrt[e/f]/g is there a way to force Mathematica always output them in the form Sqrt[h]/i eg instead of it giving Sqrt[2/3] giving Sqrt[6]/3 Regards, Michael

**Follow-Ups**:**Re: What variables are in a function and displaying surds***From:*Tomas Garza <tgarza01@prodigy.net.mx>