MM 451 Real Analysis-II
Practice Problem Set - 6
Instructor: Dharmendra Kumar UOH, Hyderabad
1. Make a sketch of the ordinate set of f over the rectangle Q and compute the volume of this
ordinate set by double integration, when f as follows:
1 − x − y if x + y ≤ 1,
(a) f : Q = [0, 1] × [0, 1] −→ R such that f (x, y) =
0 otherwise.
x + y if x2 ≤ y ≤ 2x2 ,
(b) f : Q = [0, 1] × [0, 1] −→ R such that f (x, y) =
0 otherwise.
2
x + y 2 if x2 + y 2 ≤ 1,
(c) f : Q = [−1, 1] × [−1, 1] −→ R such that f (x, y) =
0 otherwise.
(x + y)−2 if x ≤ y ≤ 2x,
(d) f : Q = [1, 2] × [1, 4] −→ R such that f (x, y) =
0 otherwise.
2. Let D be the solid bounded by the cylinder x2 + y 2 = 1 and the planes y + z = 1 and z = 0.
Find the volume of D.
3. Let D be the solid bounded by the surfaces y = x2 , y = 3x, z = 0 and z = x2 + y 2 . Find the
volume of D.
n o RR
4. Let R = (x, y) ∈ R2 : 9x2 + 4y 2 ≤ 1 . Find the R sin (9x2 + 4y 2 ) dxdy.
5. Find the volume of the solid bounded by the surfaces z = 3(x2 + y 2 ) and z = 4 − (x2 + y 2 ).
H
6. Use Green’s theorem to evaluate the line integral C y 2 dx + x dy, when:
(a) C is the square with vertices (0, 0), (2, 0), (2, 2) and (0, 2).
(b) C is the square with vertices (±1, ±1).
(c) C is the square with vertices (±2, 0) and (0, ±2).
(d) C is the circle of radius 2 and center at the origin.
(e) C has the vector equation α(t) = 2 cost, 2 sin3 t , 0 ≤ t ≤ 2π.
7. Using the change of variable formula in polar coordinate (in a Double Integral), find the volume
of the sphere of radius a.
x2 y2
8. Find the area bounded by the ellipse C := a2
+ b2
= 1.
9. Evaluate the following triple integral and make a sketch of the region of integration in each
case:
(a)
ZZZ
x y 2 z 3 dx dy dz
S
where S is the solid bounded by the surface z = xy and the planes y = x, x = 1 and z = 0.
(b)
ZZZ
x dx dy dz
S
where S is the solid bounded by the surface z = x2 + y 2 and the planes x = 0, y = 0 and z = 3.
(c)
ZZZ
1
−3
dx dy dz
S (1 + x + y + z)
where S is the solid bounded by the coordinate planes x = 0, y = 0, z = 0 and the plane
x + y + z = 1.
10. Evaluate the following integral by transforming to cylinderical coordinates:
(a)
ZZZ
(x2 + y 2 ) dx dy dz
S
where S is the solid bounded by the surface 2z = x2 + y 2 and the plane z = 2.
(b)
ZZZ
dx dy dz
S
where S is the solid bounded by the three coordinate planes, surface z = x2 + y 2 and the plane
x + y = 1.
(c)
ZZZ
(z 2 x2 + z 2 y 2 )dx dy dz
S
where S is the solid bounded by x + y 2 ≤ 1, −1 ≤ z ≤ 1.
2
11. Evaluate the following integral by transforming to spherical coordinates:
(a)
ZZZ
dx dy dz
S
where S is sphere of radius a and center at the origin.
(b)
ZZZ
dx dy dz
S
where S is region bounded by two concentric spheres of radius a and b, 0 < a < b center at
the origin .
All the best !