Download MTA

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

System of linear equations wikipedia , lookup

Integral wikipedia , lookup

Lp space wikipedia , lookup

Transcript
JRF IN MATHEMATICS 2014
Syllabus and Sample Questions for MTA
Topics for MTA (Forenoon examination): General Topology, Real Analysis,
Measure and Integration, Complex Analysis and Ordinary Differential Equations.
OUTLINE OF THE SYLLABUS
1. General topology : Topological spaces, continuous functions, connectedness,
compactness, separation axioms, product spaces, complete metric spaces, uniform
continuity, Baire category theorem.
2. Real analysis : Sequences and series, continuity and differentiability of real
valued functions of one variable and applications, uniform convergence, Riemann
integration, continuity and differentiability of real valued functions of several
variables, partial derivatives and mixed partial derivatives, total derivative.
3. Lebesgue integration : Lebesgue measure on the line, measurable functions,
Lebesgue integral, convergence almost everywhere, monotone and dominated convergence theorems.
4. Complex analysis : Analytic functions, Cauchy’s theorem and Cauchy integral formula, maximum modulus principle, Laurent series, singularities, theory of
residues, contour integration.
5. Ordinary differential equations : First order ODE and their solutions,
singular solutions, initial value problems for first order ODE, general theory of
homogeneous and nonhomogeneous linear differential equations, second order ODE
and their solutions.
1
2
SAMPLE QUESTIONS
General topology
(1) Let (X, d) be a compact metric space. Suppose that f : X → X is a function
such that
d(f (x), f (y)) < d(x, y) for x ̸= y, x, y ∈ X.
Show that there exists x0 ∈ X such that f (x0 ) = x0 .
(2) Let X be a Hausdorff space. Let f : X → R be such that {(x, f (x)) | x ∈
X} is a compact subset of X × R. Show that f is continuous.
(3) Let X be a compact Hausdorff space. Assume that the vector space of
real-valued continuous functions on X is finite dimensional. Show that X
is finite.
(4) Let n > 1 and let X = {(p1 , p2 , . . . , pn ) | pi is rational}. Show that X is
disconnected.
(5) Let A = {(x, y) ∈ R2 | max{|x|, |y|} ≤ 1} and B = {(0, y) ∈ R2 | y ∈ R}.
Show that the set A + B = {a + b | a ∈ A, b ∈ B} is a closed subset of R2 .
Real analysis and Lebesgue integration
(6) Let {an } be a bounded sequence of real numbers. For n ≥ 1, Define
sn =
(a1 + a2 + . . . + an )
.
n
Show that lim inf an ≤ lim inf sn .
n→∞
n→∞
(7) Let p (x) be an odd degree polynomial in one variable with coefficients from
the set R of real numbers. Let g : R → R be a bounded continuous function.
Prove that there exists an x0 ∈ R such that p (x0 ) = g (x0 ).
(8) Suppose that U is a connected open subset of R2 and f : U → R is such
∂f
that ∂f
∂x ≡ 0 and ∂y ≡ 0 on U . Show that f is a constant function.
(9) Let f1 , f2 , f3 , . . . and f be nonnegative Lebesgue integrable functions on R
such that
∫y
∫y
lim
fn (x)dx =
f (x)dx,
n→∞
−∞
−∞
for each y ∈ R ∪ {∞}. Show that lim inf
n→∞
∫
U
fn (x)dx ≥
∫
U
f (x)dx for any open
subset U of R.
(10) Let f be a uniformly continuous real valued function on the real line R.
Assume that f is integrable with respect to the Lebesgue measure on R.
Show that f (x) → 0 as |x| → ∞.
3
∫∞
(11) Let f : R −→ [0, ∞) be a measurable function. If −∞ f (x)dx = 1 then
∫∞
prove that −∞ 1+f1(x) dx = ∞.
(Hint: First show that m{x ∈ R | f (x) < 1} = ∞ where m is the Lebesgue
measure.)
Complex analysis
(12) Suppose for an analytic function f its zero set Zf is uncountable. Show
that f ≡ 0.
1
for each n ∈ N.
(13) Let f : C −→ C be analytic. Suppose that |f ( n1 )| ≤ n3/2
1
2
Prove that {n f ( n )} is bounded.
(14) Let f : C −→ C be continuous. If f 2 and f 3 are analytic prove that f is
analytic at every point of C.
Ordinary differential equations
(15) Let y : [a, b] → R be a solution of the equation
dy
d2 y
+ P (x)
+ Q (x) y (x) = 0,
dx2
dx
where P (x) and Q (x) are continuous functions on [a, b]. If the graph of
the function y (x) is tangent to X-axis at any point of this interval, then
prove that y is identically zero.
(16) Let f : R → R be a continuous function. Consider the differential equation
y ′ (t) + y(t) = f (t)
(∗)
on R.
(a) Show that (∗) can have at most one bounded solution.
(b) If f is bounded, show that (∗) has a bounded solution.
(17) Let p ∈ C. Consider the differential equation
u′′ (x) − p2 u(x) = 0.
If every solution, u : (−∞, ∞) → C, of this equation satisfies
∫ T
1
sup
|u(t)|dt < ∞,
T >0 2T −T
prove that Real(p) = 0.