- #1
swampwiz
- 571
- 83
I was reviewing the Cardano's method formula for a real cubic polynomial having 3 real roots. It seems that to do so, the arccos (or another arc*) of a term involving the p & q parameters of the reduced cubes must be done, and then followed by cos & sin of 1/3 of the result from that arccos - and AFAIK, the only way to do this is to use the series representation of both, which seems to me to be an imperfect method. Even using the complex formula for a fractional angle results in having to get deMoivre roots, which can only be done by going through the same arc* process.
I wonder if this is so for the same reason that it is impossible to trisect an angle.
I wonder if this is so for the same reason that it is impossible to trisect an angle.