x=2 is not a solution of your original system. When you solved by hand, presumably you squared things to eliminate the square root, but that introduced the spurious solution x=2.
The solve command uses maxima currently, and I don't know exactly how it does things. Perhaps someone else can comment. For polynomial systems such solvers usually fall back on Groebner bases. Since your equation isn't in polynomial form, I think a symbolic solver would have to convert it into such a form, and then somehow check the answers in a form equivalent to the original. That seems hard but perhaps its been done for equations with square roots, or maybe there are other techniques. To get numerical solutions you can use the find_root command, and perhaps check an exact form using algdep. Hope that helps, Marshall Hampton On Jan 21, 12:14 am, Skylar <[email protected]> wrote: > I worked it out by hand to be x=2 or x=42. I get nothing useful back > from sage. What am I missing? --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
