Re: Solving simple equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg122723] Re: Solving simple equations*From*: Dana DeLouis <dana01 at me.com>*Date*: Mon, 7 Nov 2011 05:54:43 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

> ...Reduce (& Solve) doesn't work... > ...Solve[(A*n^a)^b/n == c, n] Hi. The only way I found to get a real solution for this particular problem is to use PowerExpand: data = {A -> 2, a -> 3, b -> 4, c -> 5.}; equ = PowerExpand[(A*n^a)^b/n == c] ; Solve[equ, n] Which gives: n -> (c/A^b) ^ (1/(a*b - 1)) % /. data 0.8996576447849666 Check with Solve using the same data... (A*n^a)^b/n == c /. data 16*n^11 == 5. NSolve[%, n, Reals] n -> 0.8996576447849665 = = = = = = = = = = HTH Dana DeLouis = = = = = = = = = = On Nov 5, 4:57 am, Mathieu <mat... at gmail.com> wrote: > Mathematica seems to struggle with very simple equations: > > Solve[(A*n^a)^b/n == c, n] > Solve::nsmet: This system cannot be solved with the methods available > to Solve > > Reduce doesn't work either. Even if I add assumptions: > Assuming[A > 0 && 1 > a > 0 && 1 > b > 0 && c > 0 && n > 0, Solve[(A > n^a)^b/n == c, n]] > Solve::nsmet: This system cannot be solved with the methods available > to Solve. >> > > Is there a way for Mathematica to solve these equations? > > Many thanks, > Mathieu

**Follow-Ups**:**Re: Solving simple equations***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>