determining coefficients of a polynomial

*To*: mathgroup at smc.vnet.net*Subject*: [mg124346] determining coefficients of a polynomial*From*: klw1026 <klw1026 at gmail.com>*Date*: Tue, 17 Jan 2012 03:29:01 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hi, Here's my problem: I have two rational polynomials in two variables, say x and y, with one having arbitrary coefficients. I would like to compare these two polys and solve for the arbitrary coefficients. For example, suppose the polys are $f(x,y) = \frac{2}{xy} - xy + \frac{x}{y} + \frac{y}{x}$ and $g(x,y) = \cdot\cdot\cdot + n_1\frac{1}{xy} + n_2 xy + n_3\frac{x}{y} + n_4\frac{y}{x} +\cdot\cdot\cdot$. Then you can see that $n_1 = 2$, $n_2=-1$, $n_3 = n_4 =1$ and all other $n_i = 0$. Does anyone know how to do this with Mathematica? Thanks