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- Path: sparky!uunet!usc!chaph.usc.edu!aludra.usc.edu!not-for-mail
- From: rmurphy@aludra.usc.edu (Bob Murphy)
- Newsgroups: sci.math
- Subject: Re: Pi in beatiful form --lost
- Date: 16 Dec 1992 02:14:38 -0800
- Organization: University of Southern California, Los Angeles, CA
- Lines: 45
- Message-ID: <1gmvieINN7al@aludra.usc.edu>
- References: <BzBt9q.2HM@unccsun.uncc.edu>
- NNTP-Posting-Host: aludra.usc.edu
-
- In article <BzBt9q.2HM@unccsun.uncc.edu> sbardhan@uncc.edu writes:
- >I hope Mathematicians especially Pi'ans could help me remember this beautiful form of pi.
- >I can only faintly remember this beautiful form invented by Ramanujam
- >pi = (1*2)/(3*4) +(5*6)/(6*7)....
- >
- >All I remember is that it is very close to this representation ....it involved multiplication of two numbers
- >and divsion by two very close numbers .. it was indeed one of the fascinating forms.
- >
- >Thanks
- >--bardhan
- >
-
- John Wallis came up with the following in the middle of the 17th century.
-
- pi/2 = 2/1 * 2/3 * 4/3 * 4/5 * 6/5 * 6/7 * ...
-
-
- There are many other beautiful formulas involving pi.
- Here are a few of them.
-
- pi/4 = 1 - 1/3 + 1/5 - 1/7 + ...
-
- (pi - 3)/4 = 1/(2*3*4) + 1/(4*5*6) + 1/(6*7*8) + ...
-
- 4/pi = 1 + 1^2
- ------------------------------
- 2 + 3^2
- -------------------------
- 2 + 5^2
- --------------------
- 2 + 7^2
- ---------------
- 2 + 9^2
- ----------
- 2 + ...
-
- and I guess I should include Euler's:
-
- (pi^2)/6 = 1 + 1/(2^2) + 1/(3^2) + 1/(4^2) + 1/(5^2) + ...
-
-
- Bob Murphy (rmurphy@aludra.usc.edu)
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