The system is has solutions. You can use Singular, which is part of Sage: http://www.singular.uni-kl.de/Manual/3-1-0/sing_1273.htm
> ring r=0,(x,y),lp; > ideal i=x2+y2-25, x2-y2-y-5; > LIB "solve.lib"; // ** loaded /sw/share/Singular/LIB/solve.lib (1.39,2009/04/15) // ** loaded /sw/share/Singular/LIB/triang.lib (1.14,2009/04/14) // ** loaded /sw/share/Singular/LIB/elim.lib (1.34,2009/05/05) // ** loaded /sw/share/Singular/LIB/ring.lib (1.34,2009/04/15) // ** loaded /sw/share/Singular/LIB/primdec.lib (1.147,2009/04/15) // ** loaded /sw/share/Singular/LIB/absfact.lib (1.7,2008/07/16) // ** loaded /sw/share/Singular/LIB/matrix.lib (1.48,2009/04/10) // ** loaded /sw/share/Singular/LIB/nctools.lib (1.54,2009/05/08) // ** loaded /sw/share/Singular/LIB/random.lib (1.20,2009/04/15) // ** loaded /sw/share/Singular/LIB/poly.lib (1.53,2009/04/15) // ** loaded /sw/share/Singular/LIB/inout.lib (1.34,2009/04/15) // ** loaded /sw/share/Singular/LIB/general.lib (1.62,2009/04/15) > def R=lex_solve(std(i)); // 'lex_solve' created a ring, in which a list rlist of numbers (the // complex solutions) is stored. // To access the list of complex solutions, type (if the name R was assigned // to the return value): setring R; rlist; > setring R; rlist; [1]: [1]: -3.645398168574155899469652036354 [2]: -3.422144385112380095048443186522 [2]: [1]: 3.645398168574155899469652036354 [2]: -3.422144385112380095048443186522 [3]: [1]: -4.057224690913259002509197930026 [2]: 2.922144385112380095048443186522 [4]: [1]: 4.057224690913259002509197930026 [2]: 2.922144385112380095048443186522 Michael --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---