Alex Miller Alex
Posted on Thursday, 30 January, 2003 - 11:28 pm:

Lim N*Sin[2*pi*e*N!] as N tends to infinity. can anyone please help. I must be missing something easy.
Alex Miller Alex
Posted on Friday, 31 January, 2003 - 12:10 am:

It goes to 2*Pi but how?
David Loeffler
Posted on Friday, 31 January, 2003 - 09:13 am:

Try substituting in the series expansion for e, that is
e= ¥
å
r=0 
1
r!
You should find that you get a lot of integer terms, which can be thrown away as sin x=sin(x+2pn), a term 1/(n+1) and lots of terms that are too small to matter. What you get is thus asymptotically
N sin æ
ç
è
2p
N+1
+O( 1
n2
) ö
÷
ø
~ 2pN
N+1
~ 2p
David
Alex Miller Alex
Posted on Friday, 31 January, 2003 - 09:10 pm:

thank you very much.

-Alex Miller
Alex Miller Alex
Posted on Friday, 31 January, 2003 - 09:14 pm:

By the way I really like your site; you have done some beautiful problems.