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