This program is supplied without representation or warranty of any kind. Michael Harwood 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.

Using Quad is simple. Run the program, enter the numbers a, b, and c.
Press `R/S` and the two roots are left in stack registers X and
Y.

Stack Contents | ||||

CODE | X | Y | Z | T |

01LBL"QUAD" 02 "ENTER a,b,c" 03 TONE 0 04 PROMPT 05 RCL Z 06 CHS 07 ST/ Z 08 / 09 X<>Y 10 2 11 / 12 STO Z 13 STO T 14 X^2 15 + 16 SQRT 17 ST- Z 18 + 19 END |
c a -a -a -c/a -b/a 2 -b/2a -b/2a -b/2a b^2/4a b^2/4a-c/a sqrt sqrt -b/2a+sqrt |
b c c c -b/a -c/a -b/a -c/a -c/a -c/a -c/a -b/2a -b/2a -b/2a -b/2a-sqrt |
a b b -b/a -c/a -b/2a -b/2a -b/2a -b/2a -b/2a -b/2a-sqrt -b/2a |
-b/2a -b/2a -b/2a -b/2a -b/2a -b/2a |

The roots (solutions) areKEYSTROKES DISPLAY COMMENTSXEQ "QUAD" ENTER a,b,c 3 3 ENTER 3 Enter a 1 1 ENTER 1 Enter b 2 2 CHS -2 Enter c R/S 0.666667 Root 1 x<>y -1 Root 2

If the equation has imaginary roots then it will stop at line 16 and display "DATA ERROR"

Go back to the HP-41 software library

Go back to the general software library

Go
back to the main exhibit hall