4 Sep
2011
4 Sep
'11
4:34 p.m.
On Sat, Aug 6, 2011 at 3:11 PM, Bill Gosper <billgosper@gmail.com>wrote:[...] Recall that quartic solutions in general have quadratic surds inside cubic
surds inside quartic surds,
No, Julian points out that In[642]:= Position[Solve[x^4 + c*x^2 + d*x + e == 0, x][[1]], _^(1/4)|_^(-1/4)] Out[642]= {} I.e. Mathematica does it with square roots of square roots of cube roots of square roots. However in Macsyma, reveal(solve(x^4+c*x^2+d*x+e,x)[1],7) Sum(4) sqrt(------) sqrt(- Quotient) Expt x = - ---------------- - ------------ 1/4 6 6 Quotient --rwg