360 CHAPTER 19. THE RIEMANNN INTEGRAL ON Rn
∫ 10∫ z
0∫ 2z
0 f (x,y,z) dxdydz =∫ ?
?∫ ?
?∫ ?
? f (x,y,z) dydzdx,∫ 10∫ z
0∫ z
0 f (x,y,z) dxdydz =∫ ?
?∫ ?
?∫ ?
? f (x,y,z) dzdydx,∫ 10∫√z
z/2
∫ y+z0 f (x,y,z) dxdydz =
∫ ??∫ ?
?∫ ?
? f (x,y,z) dxdzdy,∫ 64∫ 6
2∫ 4
0 f (x,y,z) dxdydz =∫ ?
?∫ ?
?∫ ?
? f (x,y,z) dzdydx.
3. Find the volume of R where R is the bounded region formed by the plane 15 x+ y+
14 z = 1 and the planes x = 0,y = 0,z = 0.
4. Find the volume of R where R is the bounded region formed by the plane 15 x+ 1
2 y+14 z = 1 and the planes x = 0,y = 0,z = 0.
5. Find the volume of R where R is the bounded region formed by the plane 15 x+ 1
3 y+14 z = 1 and the planes x = 0,y = 0,z = 0.
6. Find the volume of the bounded region determined by 3y+ z = 3,x = 4− y2,y =0,x = 0.
7. Find the volume of the region bounded by x2 + y2 = 16,z = 3x,z = 0, and x≥ 0.
8. Find the volume of R where R is the bounded region formed by the plane 14 x+ 1
2 y+14 z = 1 and the planes x = 0,y = 0,z = 0.
9. Here is an iterated integral:∫ 3
0∫ 3−x
0∫ x2
0 dzdydx. Write as an iterated integral in thefollowing orders: dzdxdy, dxdzdy, dxdydz, dydxdz, dydzdx.
10. Find the volume of the bounded region determined by 2y+ z = 3,x = 9− y2,y =0,x = 0,z = 0.
11. Find the volume of the bounded region determined by y+ 2z = 3,x = 9− y2,y =0,x = 0.
12. Find the volume of the bounded region determined by y+z = 2,x = 3−y2,y = 0,x =0.
13. Find the volume of the region bounded by x2 + y2 = 25,z = x,z = 0, and x≥ 0.
Your answer should be 2503 .
14. Find the volume of the region bounded by x2 + y2 = 9,z = 3x,z = 0, and x≥ 0.
19.4.1 Mass And DensityAs an example of the use of triple integrals, consider a solid occupying a set of pointsU ⊆ R3 having density ρ . Thus ρ is a function of position and the total mass of the solidequals
∫U ρ dV . This is just like the two dimensional case. The mass of an infinitesimal
chunk of the solid located at x would be ρ (x) dV and so the total mass is just the sum ofall these,
∫U ρ (x) dV .
Example 19.4.1 Find the volume of R where R is the bounded region formed by the plane15 x+ y+ 1
5 z = 1 and the planes x = 0,y = 0,z = 0.