Re: Extracting terms from an equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg69786] Re: Extracting terms from an equation*From*: dimmechan at yahoo.com*Date*: Sat, 23 Sep 2006 04:44:13 -0400 (EDT)*References*: <eevubf$hqu$1@smc.vnet.net>

Can someone explain the difference in the following? Cases[a + b*x^2 + c*y^2 + d*x*y + e*x^3, _?( !FreeQ[#1, x] & )] {b*x^2, e*x^3, d*x*y} Cases[a + b*x^2 + c*y^2 + d*x*y + e*x^3, _?(MemberQ[#1, x] & )] {d*x*y} Thanks Î?/Î? Coleman, Mark ÎÎ³Ï?Î±Ï?Îµ: > Greetings, > > I'd like to find a general way to extract all of the terms from an > equation that involve a given variable. For instance, consider the > equation > > myEquation == Exp[a + b x^2 + c y^2 + d x y + e x^3]] > > I'd like to define a function such that > > myFunction[myEquation,x] returns the result {b x^2, d x y, e x^3} > > Thanks, > > -Mark

**Follow-Ups**:**Re: Re: Extracting terms from an equation***From:*"Carl K. Woll" <carlw@wolfram.com>