2. Let {xn}nEN be a sequence in R converging to x 0. Show that the sequence R. Assume that x 0 an...
#s 2, 3, 6 2. Let (En)acy be a sequence in R (a) Show that xn → oo if and only if-An →-oo. (b) If xn > 0 for all n in N, show that linnAn = 0 if and only if lim-= oo. 3. Let ()nEN be a sequence in R. (a) If x <0 for all n in N, show that - -oo if and only if xl 0o. (b) Show, by example, that if kal → oo,...
Example: Let {xn} be a sequence of real numbers. Show that Proposition 0.1 1. If r is bounded above, x = lim sup (r) if and only if For all 0 there is an NEN, such that x <x+e whenevern > N, and b. For all >0 and all M, there is n > M with x - e< In a. Example: Let {xn} be a sequence of real numbers. Show that Proposition 0.1 1. If r is bounded above,...
4. (20 pts) Let {xn} be a Cauchy sequence. Show that a) (5 pts) {xn} is bounded. Hint: See Lecture 4 notes b) (5 pts) {Jxn} is a Cauchy sequence. Hint: Use the following inequality ||x| - |y|| < |x - y|, for all x, y E R. _ subsequence of {xn} and xn c) (5 pts) If {xnk} is a See Lecture 4 notes. as k - oo, then xn OO as n»oo. Hint: > d) (5 pts) If...
Let (X, d) be a compact metric space, and con- sider continuous functions fk : X → R, for k N, and f : X → R. Suppose that, for each the sequence (fe(x))ke N 1s a monotonic sequence which converges to (x). Show that r є X, k)kEN Converges to j uniformly. Let (X, d) be a compact metric space, and con- sider continuous functions fk : X → R, for k N, and f : X → R....
Please help! Only answer questions 5-8! Definition 0.1. A sequence X = (xn) in R is said to converge to x E R, or x is said to be a limit of (xif for every e > 0 there exists a natural number Ke N such that for all n > K, the terms Tn satisfy x,n - x| < e. If a sequence has a limit, we say that the sequence is convergent; if it has no limit, we...
A function from N to a space X is a sequence n-xn in X. A sequence in a topological space converges to a point x E X if for each open neighborhood U of x there exists a є N such that Tn E U for all n 2 N. c) Consider the (non-Hausdorff) space S1,2,3 equipped with the indiscrete topology; that is, the only open sets are and S. Let n sn be an arbitrary sequence in S. Show...
Let f : D → IR with x0 and accumulation point of D. f has a limit at x0 if and only if for each sequence {xn} ∞ n=1 converging to x0 with xn ∈ D and xn 6= x0 for all n, the sequence {f(xn)} ∞ n=1 converges. Let f:D + R with , and accumulation point of D. f has a limit at zo if and only if for each sequence {In}n=1 converging to to with In E...
Let (an)nen be a bounded sequence in R. For all n e N define bn = sup{am, On+1, On+2,...}. (You do not have to show that the supremum exists.) (a) Prove that the sequence (bn)nen is a monotone sequence. (b) Prove that the sequence (bn)nen is convergent. (c) Prove or disprove: lim an = lim bre. 100 000
(4) Let(an}n=o be a sequence in C. Define R-i-lim suplanlì/n. Recall that R e [0,x] o0 is the radius of convergence of the power series Σ a (z 20)" Assume that R > 0 (a) Prove that if 0 < ρ < R, then the power series converges uniformly on the closed (b) Prove that the power series converges uniformly on any compact subset of the disk Ix - xo< R (4) Let(an}n=o be a sequence in C. Define R-i-lim...
8. More generally, let X be any infinite-dimensional vector space equipped with an inner product ,) in such a way that the induced metric is complete. In particular, there is a norm on X defined by and the metric is given by d(r, y) yl Let A denote the unit ball A x E X < 1} We know that A is closed and bounded essentially from the definitions. Show that A is not compact. (Hint: Construct a sequence xn...