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23 Nov 2016: Mich. 2016 NUMBERS AND SETS—EXAMPLES 4 PAR. 1. The symmetric difference A4B of two sets A and B is defined to be the set of elements x such that xis ... 11. Let S be a collection of subsets of N such that for all A, B S we have A B or B A.

13 May 2016: If φ : (Sn,) (B,B) , show that we can find a mapΦ : X E such that p Φ = φ π and Φ(Sn1 0) =. If we define φ =Φ|Sn11 : Sn1 ... Show that there are maps Ap : TpM TpM such that ifv,w TpM, ω(v,w) = 〈Apv,w〉.

15 Feb 2016: 7. Let R be an integral domain. The greatest common divisor (gcd) of non-zero elements a andb in R is an element d in R such that d divides both ... b) Show that may be identified with the set Fq{} in such a way that GL2(Fq) acts on as the group of

17 Oct 2016: ii) Let α be such that |K(α) : K| is odd. ... and let β = α4.Find. rationals a, b, c such that β = a bα cα2.

14 Oct 2016: c) Let x be a non-zero rational number. Show that there is a rational number y such thatxy = 1. ... d) Show that if a and b are natural numbers such that a is a factor of b then a 6 b.

13 May 2016: p. k, where k is the smallest value ofn such that xn 6= yn. ... Hint:first find a subsequence (fni ) such that fni (x) converges for all x Q [0, 1].)Deduce that the closure of B in (C[0, 1], d) is compact.

27 Oct 2016: b) If (fn) does not converge uniformly, show that there is a convergent sequence (xm) x [0, 1] such that (fn(xn)) does not converge to f(x). ... a) The space Cb(R) of bounded continuous functions on R.(b) The space C0(R) of continuous functions f : R R

23 Nov 2016: Mich. 2016 NUMBERS AND SETS—EXAMPLES 4 PAR. 1. The symmetric difference A4B of two sets A and B is defined to be the set of elements x such that xis ... 11. Let S be a collection of subsets of N such that for all A, B S we have A B or B A.

28 Oct 2016: 7. A map π : E B is called a covering map if there is an open cover {Uα} of B such that π1(Uα)is a disjoint union. ... H(B) H(E) such that π π! is multiplication by N.

21 Nov 2016: If A is the matrix of the first of these (say), find a non-singular matrix P such that PTAP is diagonalwith entries 1. ... 15. Let a1, a2,. , an be real numbers such that a1 an = 0 and a21 a2n = 1.

26 Oct 2016: 4. (a) Show that if x 6= y are vectors in the finite dimensional vector space V , then there is a linearfunctional θ V such that θ(x) 6= ... fn for V such that. ψ.  mi=1. xiei,. nj=1. yjfj.

14 Oct 2016: c) Let x be a non-zero rational number. Show that there is a rational number y such thatxy = 1. ... d) Show that if a and b are natural numbers such that a is a factor of b then a 6 b.

22 Oct 2016: 6. Let X, Y be manifolds. A submersion is defined to be a smooth map f : X Y such thatdfx is surjective for all x X. ... zero outside the ball of radius b > a, and such that f(Rn) [0, 1].These functions are very useful for gluings.

11 Nov 2016: Let x0 and 0 < ρ < ρ̄ be such that the ball B(x0, ρ̄). ... where b Rd and c R. Show that there exists a constant C such thatB(x0,ρ).

12 Dec 2016: 7. For K C nonempty and compact, find a Hilbert space H and T B(H ) such that σ(T ) = K. ... sense for any z0 U there exists an open neighbourhood N U of z0 such that f can be represented on.

14 Oct 2016: 1. Calculate d = (a,b) and find integers r and s such that ra sb = d when. ... iii) Find constants c and d such that λ(a,b) 6 c log b d.

14 Oct 2016: Show that there is a positive integer n such that an = e, the identity element.(The least such positive n is the order of a.). ... b) Show that there exists a positive integer n such that an = e for all a G.(The least such positive n is the exponent of G.

15 Feb 2016: 7. Let R be an integral domain. The greatest common divisor (gcd) of non-zero elements a andb in R is an element d in R such that d divides both ... b) Show that may be identified with the set Fq{} in such a way that GL2(Fq) acts on as the group of

29 Feb 2016: 8. By a selection function for a set a, we mean a function s: Pa Pa such that s(b) b for allb a, both inclusions being strict unless b is ... First show that there exists β < α such that |f(β) f(γ)| < 1 for allγ > β.].

27 Oct 2016: algebra. 1.2. Show that the following sets of subsets of R all generate the same σ-algebra:(a) {(a,b) : a < b}, (b) {(a,b] : a < b}, (c) {(,b] : b ... an,bn] such that the Lebesgue measure of A4B(= (Ac B) (ABc)) is less than ε.