Inaccurate numerical result for roots of square equation
Hi,I have 'Sage Version 4.6.1, Release Date: 2011-01-11' and I using next code to get roots of square equation:
reset() var('a b c p pz pz2') a = 0.0000148294611962432 b = 9.90113840830450 c = 1.00000000000000 A = a*p^2 + b*p + c pz = solve(A == 0, p, solution_dict = True) pz = [s[p].n() for s in pz]; Result1 = A(p=pz)
This way give very bad accuracy of the 1st root (Result1=-0.00138422288000584). What i do wrong? And How to get precision result with Sage? Thanks!