Given the following triple integral:
$-\iiint_D (x^2 + y^2 + z^2 -4) \,dV$
How can I find the closed surface out of which the above integral is maximal? I am using the divergence theorem to calculate flux through a surface.
Given the following triple integral:
$-\iiint_D (x^2 + y^2 + z^2 -4) \,dV$
How can I find the closed surface out of which the above integral is maximal? I am using the divergence theorem to calculate flux through a surface.
The integral is maximized for the largest set $\subseteq \mathbb{R}^3$ for which $f(x,y,z) = -(x^2+y^2+z^2-4)$ remains positive, i.e., when $$ x^2+y^2+z^2\le 4 $$ which is indeed the closed ball of radius $2$ centered at the origin.