Hello.

Is there anyone to know a formula to determine the circumference of ellipse(x2/a2+y2/b2=1).

Thanks in advance.

have a look at http://forum.swarthmore.edu/dr.math/...q.ellipse.html

There is a neat approximation which has a maximum error of 0.4%. After Roger Maertens.

Perimeter = ((a^y+b^y)^(1/y))*4

where a,b = major/minor semi axis y = const = ln(2)/(ln(pi/2))

Hope that's helpful!

Or you could always do a little numerical integration.

dan