HP 12C can't do decimal factorial

[Gamo]

HP 12C return decimal factorial to Error#0
HP 15C able to do this for example 0.5! = 0.886227

Is there any work around to do this on HP 12C ?

Gamo

[Gene]

The 12c has never been able to do the **gamma** function. The owners manual states specifically that it is an error.

Searching the museum forum archives produces this result... which did not take very long to search for, BTW.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...ead=146362

[Dieter]

(10-18-2017 03:18 PM)Gamo Wrote:  HP 12C return decimal factorial to Error#0
HP 15C able to do this for example 0.5! = 0.886227

Sure. The 12C calculates the factorial – which is defined for non-negative integer arguments. So just like on the HP41, HP67 and many other HPs everything else throws an error. Which is perfectly correct.

The 34C, 15C, 35s and some other HPs do not calculate x! but actually Γ(x+1). Which for integer arguments is the same as x!. So if you want to calculate Γ(1,5) = ½√π = 0,886... you can do so by evaluating 0,5! on these special calculators.

BTW take a look at the keyboard of the 12C and 15C. On the 15C the key label is "x!" while on the 12C it's "n!" – since the argument has to be a natural number.

(10-18-2017 03:18 PM)Gamo Wrote:  Is there any work around to do this on HP 12C ?

No. The 12C has no Gamma function.

Dieter

[jebem]

(10-18-2017 04:11 PM)Gene Wrote:  Searching the museum forum archives produces this result... which did not take very long to search for, BTW.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...ead=146362

The Viktor's RSKEY site url referenced in the above URL contents is outdated.
This is an updated link for Viktor's site on HP 12C information and a Gamma program for the HP 12C.

[Gamo]

Thank You everyone, very useful information.


Gamo