HP calculators: origin of prefix key labels f and g  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: HP calculators: origin of prefix key labels f and g (/thread234293.html) 
HP calculators: origin of prefix key labels f and g  M Habl  11212012 I am wondering about the motivation of HP developers to label the prefix keys of the RPN calculators in the 70s and 80s by the letters f and g. Obviously, the reason was not absolutely substantive as later angled arrows were invented instead.
Re: HP calculators: origin of prefix key labels f and g  Walter B  11212012 In mathematics, f and g are common names for arbitrary functions. The first appearance of these named prefixes was on the HP65, which had f, f^(1), and g, as you can see in this very museum. I think HP took these letters from math  but that's just my personal view.
Re: HP calculators: origin of prefix key labels f and g  Gerson W. Barbosa  11212012 You are absolutely right.
Re: HP calculators: origin of prefix key labels f and g  Eric Smith  11212012 I was a bit disappointed when they left the "f" designation off of the gold shift key on the HP41C, but somehow I learned to cope. I was happy to see my old friends "f" and "g" again on the Voyager series.
Re: HP calculators: origin of prefix key labels f and g  Luiz C. Vieira (Brazil)  11212012 I, too, follow your reasoning.
Re: HP calculators: origin of prefix key labels f and g  Eddie W. Shore  11212012 Quote: I don't know the official reason, but I always assumed that since f and g were common names for functions (f(x), g(x)), HP used f and g as names for alternate functions.
Eddie
Re: HP calculators: origin of prefix key labels f and g  BobVA  11212012 My high school buddy and I shared a certain amount of astonishment when we saw the "h" shift on the HP67. This was surely the last word in computation! :)
Bob
Re: HP calculators: origin of prefix key labels f and g  John M (Ottawa)  11212012 Now a better question  when did the practice of using f(x) and g(x) for functions originate? The earliest calculus textbook I have from late 1800s already used f(x) and g(x). Does this originate back to Sir Isaac Newton himself?
Re: HP calculators: origin of prefix key labels f and g  Gerson W. Barbosa  11212012 The notation f(x) for a function of x was first used by Leonard Euler, according to this book: Re: HP calculators: origin of prefix key labels f and g  Thomas Radtke  11222012 It all started with a gold key on the 45, so I take it as a reminicence to the classics. Other calculators like the 27S followed with a plain blue shift key for blue labelled functions.
