сверху - плоскостью z=4-x-y
V= ∫ ∫_(x^2+y^2 ≤ 4)(4-x-y)dxdy
Полярные координаты:
x= ρ cos φ
y= ρ sin φ
dxdy= ρ d ρ d φ
0 ≤ p ≤ 2
0 ≤ φ ≤ 2π
V= ∫^(2π)_(0) ∫^(2)_(0) (4-ρ cos φ -ρ sin φ ) ρ d ρ d φ =
=∫^(2π)_(0) ([blue]∫^(2)_(0) (4 ρ -ρ^2 cos φ -ρ^2 sin φ )d ρ [/blue]d φ =
=∫^(2π)_(0) ([blue] (2 ρ^2 -(ρ^3/3)* cos φ -(ρ^3/3)* sin φ )|^(2)_(0) [/blue]d φ =
=∫^(2π)_(0) ([blue] (2 *2^2 -(2^3/3)* cos φ -(2^3/3)* sin φ ) [/blue]d φ =
=∫^(2π)_(0)(8-(8/3)cos φ -(8/3)sin φ )d φ =
=(8 φ -(8/3)sin φ +(8/3)cos φ )|^(2π)_(0)=
=8*2π-(8/3)*0+(8/3)*(1-1)=16π