Oups I just saw that my first and second relationals are the same. So I have to solve for only 3 relationals.
I just went to try the wolfram alpha online calculator, I got : 1/ for the first relational : solve((-k**8 + 8*k**6 - 8*k**4 - 16*k**2 - 64)/(k*(k**8 - 2*k**6 - 4*k**4 - 16*k**2 + 8)) > 0, k > 2, k <= 3) alpha gives: 2<k<sqrt(2/3 (2+(53-3 sqrt(201))^(1/3)+(53+3 sqrt(201))^(1/3))) 2/ for the third one: solve((k**8 - 6*k**6 + 8*k**2 + 96)/(k*(k**8 - 2*k**6 - 4*k**4 - 16*k**2 + 8)) >= 0, k > 2, k <= 3) alpha gives: sqrt(2/3+1/3 (404-36 sqrt(109))^(1/3)+1/3 2^(2/3) (101+9 sqrt(109))^(1/3))<=k<=3 3/ and for the fourth one: solve((k**8 - 2*k**7 + 4*k**6 + 4*k**5 - 16*k**4 + 8*k**3 - 40*k**2 + 24*k - 64)/(k*(k**8 - 2*k**6 - 4*k**4 - 16*k**2 + 8)) >= 0, k > 2, k <= 3) alpha gives: 2<k<=3 Bruno -- 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. 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/004501b1-b4a1-416d-acc4-862329a485c4%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.