Is there any reason that we should return something other than -2 for the cube root of -8?
>>> root(-8,3) 2*(-1)**(1/3) >>> _.n() 1.0 + 1.73205080756888*I Of course real_root was written to work around this, but if odd powers just removed a simple negative it wouldn't be necessary. >>> real_root(-8,3) -2 Note that the -1 does not always appear raised to the fractional power: >>> root(-8,3) 2*(-1)**(1/3) >>> root(-9,3) (-9)**(1/3) When I make the change to make things like root(-8, 3) return -2, no tests fail. Is this a change we should make? -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
