Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » sci.math.* » sci.math

Topic: Ellipse circumference in workable closed form
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
thomasinventions@yahoo.com

Posts: 35
Registered: 12/23/11
Ellipse circumference in workable closed form
Posted: Dec 16, 2012 1:17 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

http://arithmeticgeometricmean.blogspot.com

8e^2(1-e^2)*d/dk(K(k=e^2))+2(1-e^2)*pi/(AGM(1,sqrt(1-e^2)))

The derivative of K is estimated with a small delta applied to the form involving the AGM:

[pi/(2*AGM(1,sqrt(1-(e^2+1E-26))))-pi/(2*AGM(1,sqrt(1-e^2)))]/[1E-26]

At least 14 digits accuracy for all eccentricities from zero up to the point of where the aspect ratio is 1 million to 1.

Thomas Blankenhorn



Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.