(Comp.sys.hp48)
Item: 1120 by ERICLANE@UTCVM.BITNET
Author: [Prof. Eric T. Lane]
  Subj: Quad Challenge
  Date: Mon May 18 1992 19:49 

[Mini-instructions: Put quadratic equation's coefficients on the stack
 and press QD; see the two roots.  -jkh-]

[Note: I asked the network readers if they could write a shorter
 quadratic solver than mine.  They sure could!  It became a contest of
 sorts, and the winner was this clever entry.  -jkh-]

To solve the quadratic equation, try

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

which comes in at 50 bytes and 370 ticks.  There are faster routines
but they take up more bytes.

Eric T. Lane