It used to be the default behavior that Mathematica would solve polynomials of degree 4 exactly. In the current version I have (12.2.2.0) it sometimes gives numerical answers. Is there a way to change the default behavior?
Example:
Solve[1 + 320*R + 51200*R^2 - 327680*R^3 + 1048576*R^4 == 0, R]
gives the a mess with numerical answers that I can't display, even though by tweaking if I do
Solve[S^4 + 320*R * S^3 + 51200*R^2 * S^2 - 327680*R^3 S + 1048576*R^4 == 0, R]
I get back
{{R -> 1/64 ((5 + 5 I) S - 3 (-1)^(1/4) Sqrt[6] S)}, {R -> 1/64 ((5 + 5 I) S + 3 (-1)^(1/4) Sqrt[6] S)}, {R -> 1/64 ((5 - 5 I) S - 3 (-1)^(3/4) Sqrt[6] S)}, {R -> 1/64 ((5 - 5 I) S + 3 (-1)^(3/4) Sqrt[6] S)}}
(which setting S=1 is what I wanted to get in the first place).
Edit: To be clear, here are some specific things I would like to be able to do:
- Permanently disable mathematica from displaying an exact number as a numerical complex number poorly rendered inside a box:
I don't know who imagined this would be desirable as a default.
- Have settings such as SetOptions[Solve, Quartics -> True] (suggested in the comments) as default settings. (More generally, I would prefer FullSimplify to leave things as radical expressions rather than convert them to the form above (or to a form Root).
another possibly related problem: Even working with what are supposed to be "exact" quantities, Mathematica repeatedly spits out error messages of the form "Unable to decide whether numeric quantity: [messy expression involving algebraic numbers] is equal to zero. This never happened in previous versions of mathematica.