
2. If S:= {1/n - 1/min, me N}, find inf S and sup S. 4. Let S be a nonempty bounded set in R. (a) Let a > 0, and let aS := {as : S ES). Prove that inf(as) = a infs, sup(as) = a sup S. (b) Let b <0 and let b = {bs : S € S}. Prove that inf(bs) = b supS, sup(bs) = b inf S. 6. Let X be a nonempty set and...
5a) (5 pts) Find lim inf (xn) and lim sup (rn), for rn = 4 + (-1)" (1 - 2). Justify your answer 5b) (5 pts) Find a sequence r, with lim sup (xn) = 3 and lim inf (x,) = -2. 5c) (10 pts) Let {x,} be a bounded sequence of real numbers with lim inf (x,) = x and lim sup (x,) = y where , yER. Show that {xn} has subsequences {an} and {bn}, such that an...
#3 A Supremely Infimum Problem (Zorn 1.9 #8) Let S R be non-empty and bounded below. Let-S f-xlxES). Show that sup(-S) exists. Then show that -inf (S) sup(-S). This problem shows that the completeness axiom guaranteeing the existence of supremums implies a similar statement about the existence of infimums. Write down an "infimum" version of the completeness axiom. that-1
#3 A Supremely Infimum Problem (Zorn 1.9 #8) Let S R be non-empty and bounded below. Let-S f-xlxES). Show that sup(-S)...
Problem 4 [20] Suppose A C R is a non-empty set, and sup(A), inf (A) exist. Show that sup(A) inf (A) if and only if |A. Problem 5 [25]
(5) Let f: [0, 1 R. We say that f is Hölder continuous of order a e (0,1) if \f(x) -- f(y)| . , y sup [0, 1] with 2 # 1£l\c° sup is finite. We define Co ((0, 1]) f: [0, 1] -R: f is Hölder continuous of order a}. = (a) For f,gE C ([0, 1]) define da(f,g) = ||f-9||c«. Prove that da is a well-defined metric Ca((0, 1) (b) Prove that (C ([0, 1]), da) is complete...
7. Suppose f: D→C is holomorphic. Show that the diameter d= sup,, wED f(a)-f(w)of the image of f satisfies Moreover, it can be shown that equality holds precisely when f is linear, f(z)- Note. In connection with this result, see the relationship between the diameter of a curve and Fourier seri . es described in Problem 1, Chapter 4, Book I -, Layer d' whenever 0 < r < İ.] Hint 25,(0) =亦 ici r
7. Suppose f: D→C is...
Usi ng the method of (d) on p. 215, show that f (x) = 2x2 is integrable on to, is and soflolda = 3 that 3 and (d) Consider the function f(x) = x, x € (0,1). For n E N, let P, be the partition {0,1...,1}. Since ſ is increasing on [0, 1], its infimum and supremum on each interval ( 4.4) are attained at the left and right endpoint respectively. with m; = (i - 1) /nº and...
Let the function f: (a, b) → R is continuous in (a, b). If sup {f(x): x ∈ (a, b)} = L> 0 and inf {f(x): x ∈ (a, b)} = M <0, then prove that there is a c ∈ (a , b) such that f (c) = 0.
th 5. (14pt) A function defined on D C R is said to be somewhat continuous if for any e >1, (51) Prove or find a counter example for the statement "a somewhat continuous func- (52) Let EC Rm, f: ER, and a e E. Prove or disprove that f is continuous at a there is a 6 0 such that whenever z,y D and la -vl <6, then f()-)e es tion is continuous." if and only if given any...
3. (a) Given n e N, prove that sup{.22 : 0<x<1} = 1 and inf{.22n: 0<x<1} = 0. (b) Find the supremum of the set S = {Sn: ,ne N}. Give a proof.