MAR ATHANASIUS COLLEGE
MODEL QUESTION PAPER
PC3-MT01C03 MEASURETHEORY AND INTEGRATION
PART A Short Answer Questions( Answer any 5 questions. Each question has weight 1
.)
1) Define Lebesgue Outer measure of a set A. Show that [0,1] uncountable.
2) Define measurable function and show that the composition of a continuous and measurable function is measurable.
3) If ‘ f ‘is non –ve integrable function and F is defined by F(x) = x
. Prove that F is continuous
on R.
4) Show that if ‘ f ‘ is integrable then f is finite valued a.e .
5) Define signed measure. Show that
E
fd
is a signed measure.
6) Define outermeasure
induced by measure
on an algebra A .Prove that if A
A then
( )
A .
7) Show that if f
L
1
1
1
( ) and g L ( ) then fg L (
) .
8) Define convergence in measure and almost uniform convergence. Prove that almost uniform
convergence imply convergence in measure.
PART B Short Essay ( Answer any 5 questions. Each question has weight 2
.)
9) Prove that the outer measure of an interval is its length.
10) Prove that there exist measurable set which is not a Borel set.
11) Let f and g are bounded measurable functions and f=g a.e then
E
fdx
gdx
E
.Prove. Is the
converse true.Justify.
12) State and prove Lebesgue Dominated convergence theorem for measurable functions.
13) Let E be a measurable set such that 0
( )
.Then there is a +ve set A contained in E with
( )
0 .Prove
14) Let ( f n
) be a sequence of non –ve measurable functions that converges a. e on a E to a function f
then
E fd
lim
E
f d n
15) State and prove Egorov’s Theorem.
16) By integrating e
xy sin 2 y with respect to x and y show that
0 e
y sin 2 y dy y
tan 2 .
PART C Essay ( Answer any 3 questions. Each question has weight 5
.)
17) Define measurable set and prove the following. a)If
( )
0 then A is measurable. b)The class M of Lebesgue measurable sets is an algebra. c) Every interval is measurable. d) If E and E are measurable then
1 2
(
1
E
2
)
(
1
E
2
)
(
1
)
(
2
) e)Show that there exist a non measurable set.
18) A) If f and g are integrable functions show that a) af integrable and
afdx
b) f+g integrable and
f
g dx
fdx
gdx c) f integrable and
fdx
f dx .
B) Let f be an increasing real valued function on the interval [a,b].Then show that f is differentiable a.e and the derivative f’mesasurable and
b a
'
( )
( )
( ) .
19) A)State and Prove Bounded convergence theorem.
B) Let f be a bounded function defined on a measurable set E with m(E)<
.Show that f is measurable iff f inf
E
x dx
sup
f
E
( ) .
20)State and Prove a)Hahn decomposition theorem for signed measure.
b) State and Prove Lebesgue decomposition theorem.
21) Let
be a measure defined on algebra A and
the outermeasure induced by
. Then the restriction
of
to the
measurable sets is an exention of
to the
algebra containing A.
If
algebra containing A.
.If
only measure on the smallest
22) Let [
be
-finite measure space.For V x
( V x
y
( V y
) for x
X and y
write measurable and
X
Y
.Also show that the
-finite condition cannot be dropped.