trouble with pattern matching & manipulating

*To*: mathgroup at smc.vnet.net*Subject*: [mg37013] trouble with pattern matching & manipulating*From*: Troy Goodson <Troy.D.Goodson at jpl.nasa.gov>*Date*: Sun, 6 Oct 2002 05:33:06 -0400 (EDT)*Organization*: JPL/Caltech*Sender*: owner-wri-mathgroup at wolfram.com

I'm a newbie and, of course, the first thing I want to do is apparently one of the most complicated... I have an expression that looks like this: A + B/C + D*Sqrt[E]/C = 0 A,B,C,D, & E are all polynomials in x I want it to look like this (D^2)*E = (A*C + B)^2 At that point, I'll have polynomials in x on both sides. Finally, I want the equation to be written out with terms grouped by powers of x, but I think I can do that part :) I'll be very grateful to anyone who can give me some pointers. Or, at least point me to some tutorial in the Mathematica documentation. I've been looking over the documentation and I found Appendix A.5 in The Mathematica Book, but that doesn't help me. I _need_ some examples. I did find a couple of well-written posts in this newsgroup, but not quite close enough to what I want. Thanks! Troy. =-=-=-=-=-=-=-=-=-= FYI, here's the expression I'm working with. denom = Sqrt[(B^2 - r^2)^2 + 4*(r^2)*(b^2)] cnu = (2*b^2 - B^2 + r^2)/denom snu = -2*b*Sqrt[B^2 - b^2]/denom sif = 2*r*b/denom cif = (r^2 - B^2)/denom pdr = -Cos[ds]*Sin[q]*(snu*cif + cnu*sif) - Sin[ds]*(cnu*cif - snu*sif) 0 == -(B^2 - b^2)*V^2/(r^2) + (((B*V)^2)/( r^2) - 2*w*b*V*Cos[q]*Cos[ds] + (w* r)^2 - (w*r*pdr)^2)*(Cos[qr])^2 Although I said it's a polynomial in x, it's really a polynomial in "b" that I'm after.