root of a quadratic equation

[Gerson W. Barbosa]

(08-22-2015 09:41 AM)tigger Wrote:  These two equations help to solve a root of a quadratic equation:

<< 3 PICK / SWAP ROT -2 * / DUP SQ ROT - SQRT DUP2 * ROT ROT - >>

* and - at the end should be - and +, respectively:

<< 3 PICK / SWAP ROT -2 * / DUP SQ ROT - SQRT DUP2 - ROT ROT + >>

On the HP 50g, we can use

<< PICK3 / SWAP ROT -2 * / DUP SQ ROT - SQRT DUP2 - UNROT + >>

and save a few bytes. This is 50-byte long, 5 bytes shorter than my attempt at this above.

Gerson.