LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – MATHEMATICS
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THIRD SEMESTER – NOV 2006
MT 3805 – ANALYTIC NUMBER THEORY
Date & Time : 30-10-2006/9.00-12.00 Dept. No. Max. : 100 Marks
Answer ALL questions.
- a) i) Define Mobius function and Euler function
- ii) Prove that for n≥1. (2+3)
Or
iii) Prove that log n = and. (5)
- b) i) Prove that the set of all arithmetical functions f with f(1)≠0 forms an abelian group
with respect to Dirichlet product , the identity element being the function I.
Or
- ii) Let f be multiplicative. Then prove that f is completely multiplicative if and only if
f for all n1.
iii) If f is multiplicative then prove that. (10+5)
- a) i) State and prove Euler’s summation formula.
Or
- ii) Prove that where C is Euler’s constant. (5)
- b) i) State and prove weak and strong versions of Dirichlet asymptotic formulae for
the partial sums of the divisor function d(n).
Or
- ii) ) State and prove Asymptotic formulae for the partial sums of divisor functions
and (15)
III. a) i) An integer n>0 is divisible by 9 if and only if the sum of its digits in its decimal
expansion is divisible by 9. Prove this using congruences.
Or
- ii) If acand if d= (m,c), then prove that a≡b. (5)
- b) i) State and prove Lagrange’s theorem.
- ii) For any prime p prove that all the coefficients of the polynomial
f(x)=(x-1)(x-2)(x-3)…………(x-p+1)-x+1 are divisible by p. (10+5)
Or
iii) If (a,m)=1, prove that the solution of the linear congruence ax≡b (mod m) is
is given by x≡ba (mod m).
- iv) State and prove Chinese remainder theorem. (6+9)
- a) i) Let p be an odd prime. Then for all n prove that.
Or
- ii) Prove that Legendre’s symbol () is a completely multiplicative
function of n. (5)
- b) i) For every odd prime p, Prove that and
.
- ii) State and prove Gauss’ Lemma. (7+8)
Or
iii) State and prove Quadratic reciprocity law. Use it to determine those odd
primes p for which 3 is a quadratic residue and those for which it is a
nonresidue (15)
- a) i) Evaluate where P is an odd positive integer.
Or
- ii) Determine whether 888 is a quadratic residue or nonresidue of the prime 1999.
- b) i) Prove that for <1 ,,where p(0)=1 and
p(n) is the partition function.
Or
- ii) State and prove Euler’s pentagonal-number theorem. (15)