Exercise 5.17. Let {en}nez be the set of trigonometric functions. Suppose that {an}nez, {bn}nez are sequences...
Prove the following Definition 6.6.1 (Subsequences). Let (an) =) and (bn), m=0 be sequences of real numbers. We say that (bn)is a subsequence of (an) a=iff there exists a function f :N + N which is strictly increasing (i.e., f(n + 1) > f(n) for all n EN) such that bn = f(n) for all n E N.
2. Let {An}n>1 and {Bn}n>ı be two sequences of measurable sets in the measurable space (12,F). Set Cn = An ñ Bn, Dn = An U Bn: (1) Show that (Tim An) ^ ( lim Bm) – lim Cn (lim An) ( lim Bu) C lim Dm and 100 noo (2) Show by example the two inclusions in (1) can be strict.
An important fact we have proved is that the family (enr)nez is orthonormal in L (T,C) and complete, in the sense that the Fourier series of f converges to f in the L2-norm. In this exercise, we consider another family possessing these same properties. On [-1, 1], define dn Ln)-1) 0, 1,2, Then Lv is a polynomial of degree n which is called the n-th Legendre polynomial. (a) Show that if f is indefinitely differentiable on [-1,1], thern In particular,...
Let (fn) and (9n) be two sequences of functions [a, b] + R, each of which converges uniformly, lim fn = f, lim 9n = g. Suppose that f and g are bounded. Show that then, (Anon) also con- verges uniformly to fg. Please write your solution to this problem out clearly in LaTeX
Definition 5.48. Let f,g:X + Y be functions and assume that Y is a set in which the following operations make sense. Then the following are also functions: 1. f + g defined by (f +g)(x) = f(x) + g(x) for all x E X 2. f - g defined by (f – g)(x) = f(x) – g(x) for all x € X 3. f.g defined by (fºg)(x) = f(x) · g(x) for all x E X f(x) = "147...
Let (G, :) such that G = {1, - 1, i, - i} is the set of four complex numbers and · is the operation of complex multiplication. Show that G is a group and find its unity and inverses. Furthermore, let (Z4, Ⓡ ) be the additive group as per Example 1.4(iv). Define the function [G, Z., f] as f(1) = [0]4; $( - 1) = [1]4, f (i) = [2]4, f ( – i) = [3]4. Show that...
Let Mi be the set of all sequences {a.);, of real num bers such that Σ converges. More formally, we could write this as 1 lal M1a :(W) ai R and i=1 We introduce a function p: Mi x MiR by setting 95 Let (Mi,p) denote the particular metric space we introduced above, and for each X = {xīた1 e M and for each i, we refer to the number xi as the ith coordinate of X. For each N...
Let Coo denote the set of smooth functions, ie, functions f : R → R whose nth derivative exists, for all n. Recall that this is a vector space, where "vectors" of Coo are function:s like f(t) = sin(t) or f(t) = te, or polynomials like f(t)-t2-2, or constant functions like f(t) = 5, and more The set of smooth functions f (t) which satisfy the differential equation f"(t) +2f (t) -0 for all t, is the same as the...
10 Let fn be a sequence of functions that converges uniformly to f on a set E and satisfies IfGİ M for all 1,2 and all r e E. Suppose g is a continuous function on [-MI, M]. Show that g(Um(x)) uniformly to g(f(r)) on E 10 Let fn be a sequence of functions that converges uniformly to f on a set E and satisfies IfGİ M for all 1,2 and all r e E. Suppose g is a continuous...
Question 4 Exercise 1. Let G be a group such that |G| is even. Show that there exists an EG,17e with x = e. Exercise 2. Let G be a group and H a subgroup of G. Define a set K by K = {z € G war- € H for all a € H}. Show that (i) K <G (ii) H <K Exercise 3. Let S be the set R\ {0,1}. Define functions from S to S by e(z)...