coefficients but not from polynomial (variables does not work)

*To*: mathgroup at smc.vnet.net*Subject*: [mg97968] coefficients but not from polynomial (variables does not work)*From*: magdamoczydlowska at gmail.com*Date*: Thu, 26 Mar 2009 05:44:00 -0500 (EST)

Dear All, Probably my question is very simple. Suppose that we have expression a= Sin[x]+Sin[y]. I would like receive variables from which this expression is dependent, so in this case {x,y}. The Variables does not work of course in this because it is not a polynomial and it gives me {Sin[x],Sin[y]}. Do anyone know how to solve my problem. I would be very grateful for quick response. Magdalena