HP35S - Cubic (and incidentally quadratic) equations solver

[Roberto Volpi]

(04-20-2023 11:36 AM)Thomas Klemm Wrote:  

(04-20-2023 07:18 AM)Roberto Volpi Wrote:  R/S just gives ERROR 0.

From HP-15C Owner's Handbook p. 121:

Quote:Complex mode is activated

1. automatically, when executing f I or f Re<>Im; or
2. by setting flag 8, the Complex mode flag.
   

Thanks for your prompt answer.

Either set flag 8 before running the program or set it only if \(X < 0\) before calculating the square root in the following line:

Code:

   045 {          11 } √x̅

Tried again with complex mode activated, and it is ok, except when a cubic polynomial with multiple roots is entered.

Ex. x^3+3x^2+3x+1, instead of giving -1 gives ERROR 0

The same for x^3-3x^3+3x-1.