Thank you very much. How do I discard complex roots?
On Monday, December 8, 2014 4:51:26 PM UTC+2, Chris Smith wrote: > > If you don't know what extension to use you can just rebuild the > expression from the roots: > > >>> efactor = lambda e: Mul(*[(x - r)**m for r,m in > roots(e).items()]).subs( > ... x,e.free_symbols.pop()) > >>> efactor(y**6 - 20*y**4 + 77*y**2 + 242) > (y - sqrt(11))**2*(y + sqrt(11))**2*(y - sqrt(2)*I)*(y + sqrt(2)*I) > > > On Sunday, December 7, 2014 6:05:08 PM UTC-6, Paul Royik wrote: >> >> How should I use factor to factor expression over irrational numbers? >> >> For example, >> x^2-4 produces (x-2)(x+2) >> x^2-2 produces (x-sqrt(2))(x+sqrt(2)) >> x^4+1 produces (x^2-sqrt(2) x+1) (x^2+sqrt(2) x+1) >> x^2+1 produces x^2+1 (only complex roots) >> x^4-9 x^2-22 produces (x^2+2)(x-sqrt(11))(x+sqrt(11)) >> > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/d28ae417-a211-4e73-90b2-e0d4a1a79705%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
