(11C) CUBIC EQUATION

[Dieter]

(06-09-2018 12:34 PM)Gamo Wrote:  Thanks for the look up I have make update to the instruction procedure.
I hope this update make it a little more clear. Any suggestion is very welcome.

I see you were faster in reading my post than I was in deleting it. #-)
I found it may have been a little harsh, and then I found more errors that would have required even more questions and comments. So I decided to cancel my post.

But while we're at it: are you sure the program is correct? For instance R4 is not initialized. ?!?

(06-09-2018 12:34 PM)Gamo Wrote:  Remark about this program:
This program routine take about 1 minute or more to compute for the roots when used with HP-11C
With this program on HP-15C LE or 15C App this run very fast instant answer.

Maybe I can post a program that calculates the solutions directly. This should be much faster. The method is known since the 16th century (Tartaglia, Cardano). I have a HP67 program that does it. It may not fit in the 98 steps of a 19C/29C, but a translation for the 11C/15C should be easy.

Dieter