Re: how to solve this problem?

*To*: mathgroup at smc.vnet.net*Subject*: [mg95117] Re: how to solve this problem?*From*: Thomas <t.isele at gmx.de>*Date*: Wed, 7 Jan 2009 04:06:36 -0500 (EST)

Put this at the beginning: $Assumptions = {Element[x,Reals],Element[y,Reals]}; instead of Element[x,Reals] you can use x\[Element]Reals Sometimes you must call Simplify in order to get every expression neatly simlified using that Assumption.