On Tue, Sep 23, 2008 at 9:34 AM, pong <[EMAIL PROTECTED]> wrote: > > > I tried > > sage: A=matrix([[1,1],[2,3]]) > sage: A.eigenvalues() > [0.2679491924311228?, 3.732050807568878?] > > My question is why the last digit before ? in 0.2679491924311228? is > '8'? Shouldn't it be "7" according to
? means the digit before the ? is unknown. This is an algebraic number printed as an element of QQbar. You can always get it to higher precision. sage: RealField(100)(A.eigenvalues()[0]) 0.26794919243112270647255365849 William > > sage: ch=characteristic_polynomial(A) > sage: solve(ch(x)==0,x) > [x == 2 - sqrt(3), x == sqrt(3) + 2] > sage: N(2-sqrt(3), digits=18) > 0.267949192431122706 > > > > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com 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 -~----------~----~----~----~------~----~------~--~---
