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+--- Thread: Factorial equation (/thread-20674.html)
Factorial equation - Quadratica - 10-20-2023 08:39 PM
Playing about with the Prime
(n+2)! = 4*n! +4*(n+1)!
Simple to solve by hand
My attempts at getting the Prime to solve it fail.
TI nSpire CAS solves it correctly
Geo-Gebra fails
Any help is welcome.
RE: Factorial equation - calc_freak - 10-21-2023 01:07 AM
I just copied your equation and pasted it into the Solve app on my Prime emulator. Click the Num key and then the Solve soft key. It spit out 3 as the answer. Same result on my iOS version.
RE: Factorial equation - C.Ret - 10-21-2023 03:12 PM
Hi, you are welcome.
That's right, directly typing SOLVE((n+2)!=4n!+4(n+1)!,n) results in an error message (see first line in the following screenshot).
(10-20-2023 08:39 PM)Quadratica Wrote: Simple to solve by handThis is the detail of great importance that lead you to one the turnaround (see second line in screenshot).
But, there is a lot of other way to get the answer without any effort (see last entry in the screenshot).
[attachment=12697]
I hope this help a bit.
RE: Factorial equation - Quadratica - 10-21-2023 08:31 PM
Both suggestions work. It's annoying that it requires a little workaround which would not be the case on other types of equations. I didn't know that the option to specify a range for the solution existed and it's good to know.
Thank you