Re: Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?

*To*: mathgroup at smc.vnet.net*Subject*: [mg50329] Re: [mg50300] Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?*From*: DrBob <drbob at bigfoot.com>*Date*: Fri, 27 Aug 2004 02:57:51 -0400 (EDT)*References*: <200408261050.GAA16310@smc.vnet.net>*Reply-to*: drbob at bigfoot.com*Sender*: owner-wri-mathgroup at wolfram.com

Solve[x*(y/(1 + y^2)^(1/2)) == a, y] {{y -> -(a/Sqrt[-a^2 + x^2])}, {y -> a/Sqrt[-a^2 + x^2]}} Bobby On Thu, 26 Aug 2004 06:50:41 -0400 (EDT), Dick Barends <dick.barends at wxs.nl> wrote: > Hello, > > The following line > > Solve[x y / ( 1 + y^2 )^0.5 == a, y] > > Gives a complex solution : (0.+ i )a / (a^2 - x^2)^0.5 > Which is correct but could be simpler, not complex > > The solution I expected is: a/(x^2 - a^2)^0.5 > > How can I instruct Mathematica (Solve) to give the simple solution directly. > > kind regards > Dick Barends > > > > -- DrBob at bigfoot.com www.eclecticdreams.net

**References**:**Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?***From:*"Dick Barends" <dick.barends@wxs.nl>