F' on hp 15c le - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: F' on hp 15c le (/thread-5863.html) F' on hp 15c le - lrdheat - 03-12-2016 11:13 PM Can't remember program using complex capability of hp 15c le to solve f'x = 0 in order to find a max/min of f'x. This was from several years ago...somebody contributed a real neat short elegant program! f(x) is defined in program 0, f'(x)would be in program 1, dx in register .0, "x" result in program 1 would be plugged into program 0 to find f(X) at that point. RE: F' on hp 15c le - Gerson W. Barbosa - 03-12-2016 11:35 PM This one, perhaps? http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=243867 RE: F' on hp 15c le - Marcio - 03-12-2016 11:42 PM That's pure awesomeness. Thanks for posting. RE: F' on hp 15c le - lrdheat - 03-13-2016 12:26 AM That's the one! I'm glad that the post included my struggle to understand the problem with using change sign with complex numbers as well...would have forgotten that! RE: F' on hp 15c le - Ángel Martin - 03-13-2016 07:28 AM (03-13-2016 12:26 AM)lrdheat Wrote:  That's the one! I'm glad that the post included my struggle to understand the problem with using change sign with complex numbers as well...would have forgotten that! It seems it's time to dust off the 41Z... more to come.