LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – MATHEMATICS
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FIFTH SEMESTER – November 2008
MT 5505 – REAL ANALYSIS
Date : 03-11-08 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
SECTION – A
Answer ALL Questions (10 x 2=20 marks)
- Define similar sets with an example.
- If a and b are any real numbers such that
- Define a metric space.
- Give an example of a set E in which every interior point of E is also an accumulation point of E but
not conversely.
- Define a convergent sequence.
- State intermediate value theorem for continuous functions.
- Define Open ball and Closure of set E.
- When is a sequence {an} said to be Monotonic increasing and decreasing?
- State the linearity property of Riemann- Stieltjes integral.
- Define limit superior of a real sequence.
SECTION – B
Answer ANY FIVE Questions. (5 x 8=40 marks)
- State and prove Minkowski’s inequality.
- If n is any positive integer, then prove that Nn is countably infinite.
- Let(X, d ) be a metric space. Then prove that
- i) the union of an arbitrary collection of open sets in X is open in X.
- ii) the intersection of an arbitrary collection of closed sets in X is closed in
- Prove that a closed subset of a compact metric space is compact.
- Prove that every compact subset of a metric space is complete.
- Let f : ( X, d ) → Rk be continuous on X. If X is compact, then prove that f is
bounded on X.
- State and prove Rolle’s theorem.
- Let {an} be a real sequence. Then prove that
(i) {an} converges to l if and only if lim inf an = lim sup an = l
(ii) {an} diverges to + ∞ if and only if lim inf an = + ∞
SECTION C
Answer ANY TWO Questions. (2 x 20 = 40 marks)
- (a) Prove that the set R is uncountable. (10 marks)
(b) State and prove Cauchy –Schwartz inequality. (10 marks)
- (a) State and prove Bolzano- Weierstrass theorem. (18 marks)
(b) Give an example of a metric space in which a closed ball
is not the closure of the open ball B(a ; r ). (2 marks)
- (a) Let ( X, d1) and (Y, d2) be metric spaces and f : X→Y. If x0X, then prove that f is
continuous at x0 if and only if for every sequence {xn} in X that converges to x0,
the sequence { f (xn ) } converges to f (x0). (12marks)
(b) Prove that Euclidean space k is complete. ( 8 marks)
- b) State and prove Taylor’s theorem. (10 marks)