5. Suppose f : [0,1] → R is continuous, and in) is a Cauchy sequence in...
- Let V be the vector space of continuous functions defined f : [0,1] → R and a : [0, 1] →R a positive continuous function. Let < f, g >a= Soa(x)f(x)g(x)dx. a) Prove that <, >a defines an inner product in V. b) For f,gE V let < f,g >= So f(x)g(x)dx. Prove that {xn} is a Cauchy sequence in the metric defined by <, >a if and only if it a Cauchy sequence in the metric defined by...
3. Suppose that f [0,1(0,1) is a non-decreasing function (NOT assumed to be continuous). Prove or disprove that there exists x E (0,1) such that f(x)-x
Suppose fon (0,1) is uniformly continuous. Show that there is a real number A such that the function F defined by F(O)=A, F(x)=f(x) if x € (0,1), is continuous on (0,1]. (Suggestion: Show first that if {Xn}, Xn € (0,1] has lim xn = 0, then {f(xn)} is a Cauchy no sequence. Then show this sequence has the same limit no matter which {Xn} sequence going to you choose).
9. If In E (a, b) is Cauchy, f : (a,b) + R is uniformly continuous, prove that f(x) is Cauchy.
(7) Let R= {f [0,1] - R | f continuous} be the ring of all continuous functions from the interval [0,1] to the real numbers. (a) For cE [0, 1, prove that Me := {feR | f(c) = 0} is a maximal ideal of R. Hint: consider the evaluation map ec- (b) Show that if M is any maximal ideal of R then there exists a cE [0,1 such that M = Me. Hint: show that any maximal ideal M...
B2. (a) Let I denote the interval 0,1 and let C denote the space of continuous functions I-R. Define dsup(f,g)-sup |f(t)-g(t) and di(f.g)f (t)- g(t)ldt (f,g E C) tEI (i) Prove that dsup is a metric on C (ii) Prove that di is a metric on C. (You may use any standard properties of continuous functions and integrals, provided you make your reasoning clear.) 6 i) Let 1 denote the constant function on I with value 1. Give an explicit...
(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...
Let E ç R. Suppose that (felre is a sequence of continuous function from E to R 120ml o prove that if form of uniformly on Eta then fis continuous an E. e Giva an example where for f almost uniformly on E but f is not continuons on E
Problem 5 Let f : [0,1] → R be continuous and assume f(zje (0, 1) for all x E (0,1). Let n E N with n 22. Show that there is eractly one solution in (0,1) for the equation 7L IC nx+f" (t) dt-n-f(t) dt.
CELLERIA (b) (6) Suppose f is continuous. If f is restricted to [0,1] but contains no critical values in that range, what can you say, if anything, about the extreme values off on (0,1)? (u) Suppose is not continuous on (0,1). What can you say, if anything, about the extreme values off on (0,1? (e) Sketch the graph of a continuous function on (0,3) with a local minimum but no absolute minimum.