MAR ATHANASIUS COLLEGE MODEL QUESTION PAPER PC3

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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.

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