Re: trouble with pattern matching & manipulating

*To*: mathgroup at smc.vnet.net*Subject*: [mg37073] Re: trouble with pattern matching & manipulating*From*: Troy Goodson <Troy.D.Goodson at jpl.nasa.gov>*Date*: Tue, 8 Oct 2002 07:17:34 -0400 (EDT)*Organization*: JPL/Caltech*References*: <anp0p6$qvg$1@smc.vnet.net> <anrkga$3v5$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In <anrkga$3v5$1 at smc.vnet.net> Allan Hayes wrote: > Troy, > True, interactive manipulation can be difficult. > However, here is one way to do what you want. > We have to do the same thing to both sides of the equation. > > (# - D*Sqrt[K]/C)&/@(A+B/C+D*Sqrt[K]/C\[Equal]0 > > A + B/C == -((D*Sqrt[K])/C) I think I have to apologize for the lack of clarity in my original post. I had tried to word it carefully, but I deceived myself. I should have said: I have an expression that can be put into this form: A + B/C + D*Sqrt[K]/C = 0 A,B,C,D, & K are all polynomials in x I need to get it into that form and, in the end, I want it to look like this (D^2)*K = (A*C + B)^2 I think I gave the impression that I have polynomials A,B,C,D, & K at my fingertips. I don't. The expression I have is given at the end of this message. I'm still trying to digest the respones I've garned so far. In the meantime, I decided to post this clarification. > > "Troy Goodson" <Troy.D.Goodson at jpl.nasa.gov> wrote in message > news:anp0p6$qvg$1 at smc.vnet.net... >> 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[K]/C = 0 >> >> A,B,C,D, & K are all polynomials in x >> I want it to look like this >> >> (D^2)*K = (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. >> > > > >