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Re: coefficients but not from polynomial (variables does not work)

  • To: mathgroup at smc.vnet.net
  • Subject: [mg97979] Re: coefficients but not from polynomial (variables does not work)
  • From: dh <dh at metrohm.com>
  • Date: Fri, 27 Mar 2009 05:33:51 -0500 (EST)
  • References: <gqfm9a$lfv$1@smc.vnet.net>


Hi Magdalena,

you may e.g. use Cases on the lowest level to pick out symbols. Union 

ensures that each variable appears only once:



Union@Cases[Sin[x] + Sin[y], _Symbol, {-1}]



hope this helps, Daniel



magdamoczydlowska at gmail.com wrote:

> 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

> 




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