NSpire - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: Not HP Calculators (/forum-7.html) +--- Forum: Not remotely HP Calculators (/forum-9.html) +--- Thread: NSpire (/thread-15515.html) NSpire - lrdheat - 08-31-2020 12:39 AM Does one or both NSpire or NSpire CAS have the gamma function? If so, how do I find it? RE: NSpire - vaklaff - 08-31-2020 08:38 AM (08-31-2020 12:39 AM)lrdheat Wrote:  Does one or both NSpire or NSpire CAS have the gamma function? If so, how do I find it? I don't see the function in my NSpire's docs. I have the non-CAS version but after some googling I'd say the CAS version doesn't have it either. RE: NSpire - Nigel (UK) - 08-31-2020 03:39 PM On my (ancient, compared to the NSpire) TI-86 the factorial function takes fractional arguments - e.g., 2.7! If the NSpire does this you can find the gamma function, because gamma(x) = (x-1)!. I don't know whether the NSpire factorial function works for complex numbers (the TI-86 doesn't), but if you are interested in gamma(x) for real x this may help. Nigel (UK) RE: NSpire - ijabbott - 08-31-2020 03:49 PM (08-31-2020 03:39 PM)Nigel (UK) Wrote:  On my (ancient, compared to the NSpire) TI-86 the factorial function takes fractional arguments - e.g., 2.7! If the NSpire does this you can find the gamma function, because gamma(x) = (x-1)!. I don't know whether the NSpire factorial function works for complex numbers (the TI-86 doesn't), but if you are interested in gamma(x) for real x this may help. Unfortunately, the factorial operator only works on integers on the TI-NSpire, and it's the same on the TI-89 series. BTW, the "factorial" function on real or complex domain is a.k.a. the "pi" function, that is: gamma(x) = pi(x-1). RE: NSpire - vaklaff - 08-31-2020 04:06 PM (08-31-2020 03:39 PM)Nigel (UK) Wrote:  On my (ancient, compared to the NSpire) TI-86 the factorial function takes fractional arguments - e.g., 2.7! No, that doesn’t work, that I checked right after I didn’t find the gamma function in the docs. Simple google-fu shows there are multiple ways how to add the function if needed though... RE: NSpire - Pekis - 09-01-2020 10:23 AM (08-31-2020 04:06 PM)vaklaff Wrote:   (08-31-2020 03:39 PM)Nigel (UK) Wrote:  On my (ancient, compared to the NSpire) TI-86 the factorial function takes fractional arguments - e.g., 2.7! No, that doesn’t work, that I checked right after I didn’t find the gamma function in the docs. Simple google-fu shows there are multiple ways how to add the function if needed though... 2.7! = 4.1706517838 on my TI 86 ... RE: NSpire - vaklaff - 09-01-2020 07:40 PM (09-01-2020 10:23 AM)Pekis Wrote:   (08-31-2020 04:06 PM)vaklaff Wrote:  No, that doesn’t work, that I checked right after I didn’t find the gamma function in the docs. Simple google-fu shows there are multiple ways how to add the function if needed though... 2.7! = 4.1706517838 on my TI 86 ... That doesn’t work on Nspire. Sorry for not being clear...