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7 Dec 2022: Use (ii) to show that there exists b K such that det(σiσjg1(b)) 6=0. ... Deduce that if y = g1(b) then {σ(y) | σ G} is a K-basis for L.Such a basis {σ(y)} is said to be a normal basis for

19 Nov 2022: 13. Let S be a collection of subsets of N such that for every A,B S we have A B or B A.Can S be uncountable? ... Is there an uncountable collection T of subsets of N such that A B isfinite for all distinct A,B T?

11 Oct 2022: The least such n iscalled the order of g.). (b) Show that there exists a positive integer n such that gn = e for all g G. ... 10. Let H and G be groups and let X G such that 〈X〉 = G.

28 Oct 2022: 2. Given (fi)iI an arbitrary collection of continuous functions [0, 1] R such thatsupiI |fi(x)| < at each x [0, 1], show that there is an interval [a,b] [0, ... 1] witha < b such that supx[a,b] supiI |fi(x)| <. 3. Let X be a closed subspace of 1. Assume

11 Oct 2022: Find a, b, c Q such thaty = a bx cx2. ... 15. Let K and L be subfields of a field M such that M/K is finite.

13 Oct 2022: 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.

22 Nov 2022: Let a, b K such thatthe polynomials f = Xm a, g = Xm b are irreducible. ... Use a suitable Lagrange resolvent to finda Q(ζ3) such that K = Q(ζ3, 3.

28 Oct 2022: 1. Let T B(H) with |||T ||| < 1. Show that there is R B(H) such that R2 = 1 T. ... 11. Let T B(B) compact and λ 6 (σp(T) {0}). Show that T λ is bounded below.

24 Oct 2022: Ln := {w ; there are x, y W such that |y| = n 1 and w = x1y)},. ... Show that:. (a) There is a nondeterministic automaton N with n 1 states such that L(N) = Ln and(b) if D is a deterministic automaton with fewer than 2n states,

24 Oct 2022: 5. (a) Suppose that f Matn,n(F) is such that f(AB) = f(BA) for all A,B Matn,n(F) and f(I) = n.Show that f is the ... 0. Is detA > 0? 14. Let A,B in Mn(R) such that X KerA{0} with BX ImA.

1 Feb 2022: b) We say that a measurable f : Rn! C is in weak-Lp(Rn), written f 2 Lp,w(Rn) ifthere exists a constant C such that. ... Deduce. N[. i=1. Bi. 6 3n. kX. j=1. Bij. 3. b) () Suppose {Bj : j 2 J} is an arbitrary collection of balls in Rn such that each

3 Feb 2022: 1. Let A,B F be two events such that P(B) = 0 or 1. ... Ie, at least one day d such that at least k people were born on day d.).

6 Feb 2022: Regarding T as a map from C into C by identifying R2with C in the usual way, show that there exist unique complex numbers A, B such that for everyz C, ... that there need notexist holomorphic f : U C such that u = Re (f) on all of U.

1 Feb 2022: there exists 2 C such that:. u[] =. Z. R(x)dx, for all 2 D(R). () ... Rm(x, y)dy. b) Show that there exists a sequence of smooth functions fn 2 C1c (Rn) such that Tfn!

14 Nov 2022: If A is the matrix of the first of these (say), find a non-singular matrix P such that PTAP is diagonalwith entries 1. ... 14. Let a1, a2,. , an be real numbers such that a1 an = 0 and a21 a2n = 1.

24 Oct 2022: Suppose thatα: V W is a linear map such that α(Y ) Z. ... Let f be an endomorphism of E. Show theexistence and uniqueness of (F,G) vector subspaces of E such that:(a) F G = E;(b) F,G are stable by

13 Jan 2022: Prove directly from the definition thatAX has an m-variate normal distribution AX Nm(Aµ,AΣAT ). 2. Let X and Y be N(0, 1) random variables such that ... a random set C(Y ) such that Pβ,σ2 (b C(Y )) = 1 α for all β,σ2.

25 Feb 2022: Can you justify that f is unique? [Note: such a function f is called the (discrete) harmonic extension of (av). ]. ... Explain why E[|T |] = ,and find constants C,α such that P(|T | = m) Cmα.

20 Jan 2022: a) Construct a continuous surjection p : T2 T2 from the torus to itself such that for every x T2, p1(x)consists of exactly two points, and such that p is ... Such a map is called acovering map.]. (b) Show that T2 also admits a covering map p̂ : T2 K to

26 Apr 2022: Show that ϕ is convex. 5. Suppose f : X R is twice-differentiable and such that 2f(x) is positive definite for allx X. ... a) Show that the unique minimizer is x = 0. (b) Find constants 0 < m < M and L > 0 such that m f ′′(x) M and |f ′′′(x)|

4 Oct 2022: b) Now let X and Y be jointly Gaussian random vectors such that Cov(X) is positivedefinite. ... Let Qbe the equivalent probability measure such that dQ. dP eX.

4 Oct 2022: n such that Ax = 0.• There exists a y Rm with (AT y)i 0 for all i = 1,. , ... Make this assumption for the rest of the problem.(b) Why must there exist an equivalent measure Q such that 1.

12 Aug 2022: Then there is a point y / E such. that B(y,r) E 6= whenever r > 0. ... Since Uj1 isopen we can find a δj1 > 0 with δj1 δj/4 such that B(xj1,δj1) Uj1.

12 Aug 2022: Theorem 4.2. If f : [a,b] [a,b] is a continuous function, then we canfind a w [a,b] such that f(w) = w. ... Supposethat we can find a a0 < a1 < < an b such that, writing σ = ‖fP‖we have either.

1 Feb 2022: b) Find a condition on s such that x 2 Hs(Rn). ... 2u u = f. b) Show further that there exists C > 0 such that kukHs4.

17 Feb 2022: 6) Let R be an integral domain. The greatest common divisor (gcd) of non-zero elements aand b in R is an element d in R such that d divides both ... a and b, and if c divides both aand b then c divides d.

21 Nov 2022: Show that the following sets are computablyenumerable:. (a) {w ; there are three distinct words v such that f(w, v)};(b) {w ; there is a word v of even length such ... g(u, v) :=. {ffu,1(u)(v) if u K and. otherwiseis computable. (b) By the s-m-n theorem,

24 Oct 2022: similar to any of them? If so, which? Find a basis such that it is in Jordan Normal Form. ... Withoutappealing to Jordan Normal Form, show that there is a vector y such that (y,α(y),α2(y),. ,

12 Oct 2022: Mich. 2022 ANALYSIS AND TOPOLOGY—EXAMPLES 1 PAR. 1. Let (zn) be a sequence in R2 such that zn a and zn b. ... On the other hand, show that if fn does notconverge uniformly to f then we can find a convergent sequence xm x in [a,b] such that fn(xn) 6

6 Jul 2022: vd of V such that v1,. ,vr is a basis of W and the. ... vd of V such that v1,. ,vr is a basis of W the matrices.

12 Dec 2022: Then there is a point y / E such. that B(y,r) E 6= whenever r > 0. ... Since Uj1 isopen we can find a δj1 > 0 with δj1 δj/4 such that B(xj1,δj1) Uj1.

29 Nov 2022: vd of V such that v1,. ,vr is a basis of W and the. ... vd of V such that v1,. ,vr is a basis of W the matrices.

12 Dec 2022: Theorem 4.2. If f : [a,b] [a,b] is a continuous function, then we canfind a w [a,b] such that f(w) = w. ... Supposethat we can find a a0 < a1 < < an b such that, writing σ = ‖fP‖we have either.

5 Oct 2022: 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.

30 Mar 2022: In 7 we prove that such orbits admit integral representatives away from smallprimes. ... We have a Gm-action on Vgiven by λ v = λv and there is a unique Gm-action on B such that π is Gm-equivariant.

22 Feb 2022: Show that for any b C, there exists a sequence of points zn D(a,R)with zn 6= a such that zn a and f(zn) b as n. ... Find such a sequence when f(z) = e1/z, a = 0 and b = 2.[A much harder theorem of Picard says that in any neighbourhood of an essential

30 Aug 2022: and PrV then we can define a prob-ability Pr on = U V W in such a way that. ... 76. Exercise 2.4.23. Suppose such a die exists. We must have.

11 Dec 2022: There are lots of such books (because lots of different com-munities need to do first-year mathematics: engineers, students doing psyschology,science, economics, computer science, medicine. ) ... Typically,for a programming language, numbers such as

24 May 2022: Whether or not there are such things depend on whetheror not countable choice holds. ... every y such that R(y, x),and obeys the recursion wherever it is defined.

7 Oct 2022: Choose then a and b such that. 1. a. def=. 1. ... 29. Proof of Lemma 3.1.1. x K , rx > 0 such that B(x,rx).