The Museum of HP Calculators

HP Forum Archive 20

 HP 15C Programming Tutorial PostedMessage #1 Posted by Eddie W. Shore on 11 Dec 2011, 1:30 p.m. The latest installment: Part 14 (Complex Numbers)

 Re: HP 15C Programming Tutorial PostedMessage #2 Posted by Geir Isene on 11 Dec 2011, 4:16 p.m.,in response to message #1 by Eddie W. Shore Now that's a good and useful blog right there. Thanks.

 Re: HP 15C Programming Tutorial PostedMessage #3 Posted by Thomas Klemm on 14 Dec 2011, 12:40 p.m.,in response to message #1 by Eddie W. Shore The comparison of the two methods to enter complex numbers confused me slightly because in the first example you start with a stack [x y z t], enter a and b and end up with [a+ib x y y], while in the second example you start with [y z t ?]. Why? I'd start with [x y z t] as well and end up with [a+ib x y z] instead. As I always considered the stack as the interface to communicate with the calculator I don't esteem your solution to solve the quadratic equation much. You can do it without storing any numbers into registers. See message 2 in: Short quadratic solver (HP-15C) To solve your first example you'd just enter the three coefficients of the quadratic equation and run the program: ```2 ENTER 3 I 3 CHS ENTER 4 CHS I 2 Re<>Im E ``` Both solutions are now on the stack. You can use x<>y and (i) to display them. Bonus: the same program can also be used for real coefficients. Kind regards Thomas Edited: 14 Dec 2011, 12:44 p.m.

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