N and NSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg7300] N and NSolve*From*: C L C Fu <es2136 at eng.warwick.ac.uk>*Date*: Fri, 23 May 1997 01:41:29 -0400 (EDT)*Organization*: University of Warwick, UK*Sender*: owner-wri-mathgroup at wolfram.com

Hello folks I am a bit confused with N and NSolve. I sued NSolve to solve a qubic equations. It gave me three real numerical solution. However, when I used Solve to solve the same solution symbolicly, it gave me three roots in symbolic form and when I used N to solve the roots numerically, it gave me three solution in complex forms. The real parts are the same in both cases. The solutions are in the first case: {{Cp -> -8.104589570312425*^-8}, {Cp -> 2.522495922927543*^-8}, {Cp -> 4.500002377739561*^-8}} The second case: {{4.500002377739564*^-8 + 1.52201232709757*^-22*I}, {-8.104589570312425*^-8 + 2.977850205190899*^-23*I}, {2.522495922927541*^-8 - 1.720535674110297*^-22*I}} Why is that? Thanks Col