The Museum of HP Calculators


Quadratic Equation III for the HP-15C

This program is by Martin Ask and is used here by permission.

This program is supplied without representation or warranty of any kind. Martin Ask and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.

Overview

This is yet another quadratic equation program that's only 21 bytes long.

It should be noted that I'm NOT the original author of this program. It was posted in the forums quite some time ago and it seems to have failed to make it into the software library, so here it is!

Usage:

Make sure the equation is in the form "ax^2 + bx + c = 0"

Enter a, b and c in order so that they are in registers Z, Y and X respectively.

Run the program. The roots will be placed in the X and Y registers.

If you get an "Error 0", turn on complex mode (SF 8) and try again.

Listing

Line	Instr.	  Display

000		
001	LBL D	  42,21,14
002	ENTER	  36
003	ROLLUP	  43 33
004	/	  10
005	ROLLUP	  43 33
006	LST X	  43 36
007	/	  10
008	2	  2
009	CHS	  16
010	/	  10
011	ENTER	  36
012	ENTER	  36
013	X^2	  43 11
014	ROLLUP	  43 33
015	-	  30
016	SQRT	  11
017	-	  30
018	x<>y	  34
019	LST X	  43 36
020	+	  40
021	RTN	  43 32

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