OFFSET
3,4
COMMENTS
"The integral corresponds to integration over a spherical cone with opening angle Pi/2 and radius 4. However, it is not clear what the integrand physically represents (it resembles computation of a moment of inertia, but that would give a factor (rho*sin(phi))^2 rather than the given rho*cos(phi))."
REFERENCES
The Jun 02 1996 comic strip FoxTrot by Bill Amend (Amend 1998, p. 19; Mitchell 2006/2007)
LINKS
Eric Weisstein's World of Mathematics, Definite Integral
FORMULA
Equals Integral_{theta=0..2*Pi} Integral_{phi=0..Pi/4} Integral_{rho=0..4} (rho*cos(phi))*rho^2*sin(phi) d(rho) d(phi) d(theta).
EXAMPLE
100.53096491487338363080458826494409229430942078000338627119822695385012500...
MATHEMATICA
RealDigits[32 Pi, 10, 111][[1]] (* or *)
Integrate[\[Rho] Cos[\[Phi]] \[Rho]^2 Sin[\[Phi]], {\[Rho], 0, 4}, {\[Phi], 0, Pi/4}, {\[Theta], 0, 2 Pi}]
PROG
(PARI) 32*Pi \\ Altug Alkan, Dec 14 2015
CROSSREFS
KEYWORD
AUTHOR
Eric W. Weisstein and Robert G. Wilson v, Dec 14 2015
STATUS
approved