Repost: Solve: same or new bug?
- To: mathgroup at smc.vnet.net
- Subject: [mg17661] Repost: Solve: same or new bug?
- From: Thomas Gawlick <Thomas.Gawlick at uni-vechta.de>
- Date: Fri, 21 May 1999 03:37:44 -0400
- Organization: University of Vechta
- Sender: owner-wri-mathgroup at wolfram.com
In the following example Mathematica happens to find a "general solution'" that does not special to a solution for numerical specialization of the paramters a,e. m:=Sqrt[1-a^2] g:=(x*(a+y)-m*(a+y+e))^2+y^2*(a+y+e)^2-(a+y+e)^2 gx:=D[g,x] gy:=D[g,y] Solve[{g==0,gx==0,gy==0},{x,y}] {{x -> 0, y -> -a - e}, {x -> (a*(1 - a^2)^(1/2)*e)/(-1 + a^2), y -> -a}, {x -> (a*(1 - a^2)^(1/2)*e)/(-1 + a^2), y -> -a}} % /. {a->.5,e->.1} {{x -> 0, y -> -0.6}, {x -> -0.057735, y -> -0.5}, {x -> -0.057735, y -> -0.5}} a:=.5; e:=.1 Solve[{g==0,gx==0,gy==0},{x,y}] {{x -> 0., y -> -0.6}} Is the reason for this that Mathematica checks numerical solutions only? Another small question: How do you achieve to clear ALL variables? -- Best regards Thomas Gawlick --- Dr.rer.nat. Thomas Gawlick Hochschulassistent fur Didaktik der Mathematik Hochschule Vechta, 49364 Vechta