OFFSET
0,1
COMMENTS
The distance between the centers of 2 unit-radius spheres such that the volume of the overlap is equal to half the volume of each sphere. - Amiram Eldar, May 31 2021
LINKS
Eric Weisstein's World of Mathematics, Sphere-Sphere Intersection.
FORMULA
Equals 4*sin(Pi/18) = 4*A019819. - Gleb Koloskov, Feb 28 2021
EXAMPLE
0.69459271066772139540...
MATHEMATICA
RealDigits[-2*Cos[(2*Pi)/9] + 2*Sqrt[3]*Sin[(2*Pi)/9], 10, 100][[1]] (* Vaclav Kotesovec, Aug 16 2015 *)
PROG
(PARI) 4*sin(Pi/18) \\ Gleb Koloskov, Feb 28 2021
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Sep 23 2007
STATUS
approved