[Date Index] [Thread Index] [Author Index]

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

• To: mathgroup at smc.vnet.net
• Subject: [mg50300] Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?
• From: "Dick Barends" <dick.barends at wxs.nl>
• Date: Thu, 26 Aug 2004 06:50:41 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

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

• Follow-Ups:
  • Re: Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?
    • From: Murray Eisenberg <murray@math.umass.edu>
  • Re: Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
  • Re: Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?
    • From: DrBob <drbob@bigfoot.com>
  • Re: Q: Solve gives complex solution where there is a noncomplex solution how to get the last one?
    • From: jmt <jmt@dxdydz.net>