9.2.8. Suppose that E and V are subsets of Rwith E bounded, V open, and E...
No Contradiction
2. Let A and B be non-empty subsets of R, and suppose that ACB. Prove that if B is bounded below then inf B <inf A.
Question 1
1. [5 pts] Give a complete definition of lim f(x) = -oo if... 2. [25 pts] Give an example of each of the following, or state one or more theorems which show that such an example is impossible: a. A countable collection of nonempty closed proper subsets of R whose union is open. b. A nonempty bounded subset of R with no cluster points. c. A convergent sequence with two convergent subsequences with distinct limits. d. A function...
. Let C be a collection of open subsets of R. Thus, C is a set whose elements are open subsets of R. Note that C need not be finite, or even countable. (a) Prove that the union U S is also an open subset of R. SEC (b) Assuming C is finite, prove that the intersection n S is an open subset of R. SEC (c) Give an example where C is infinite and n S is not open....
Suppose that f is bounded on a, b and that for any cE (a, b), f is integrable on [c, b (a) Prove that for every e> 0, there exists CE (a, b) so that f(x)(c-a) < € for all x [a,b]. (b) For any > 0, find a partition P of [a, b so that U,P)-J f(r)dz < j and s f(r)dz L(f, P) < Hint: Do this by choosing c carefully and extending a partition of [c, b...
(e) Letf: R2-R2 be given by f(a,y) = (V-y,y) Let A, B be the subsets of R2 as indicated in the picture below. Prove that f maps A onto B. (0,1) (1;1) (-1,1) (0,1) v=1 1/2 y-axis y=x2 v-axis v -u b ets t) ide ods.a notteog (0,0) X-axis u-axis (0,0)
(e) Letf: R2-R2 be given by f(a,y) = (V-y,y) Let A, B be the subsets of R2 as indicated in the picture below. Prove that f maps A onto...
Let A, B be non-empty, bounded subsets of R. a) If the statement is true, prove it. If the statement is false, give a counterexample: sup(AUB) = max(sup(A), sup(B)}. b) If the statement is true, prove it. If the statement is false, give a counterexample: If An B + Ø, then sup(A n B) = min{sup(A), sup(B)}. E 选择文件
(a) Suppose K is a compact subset of a metric space (X, d) and x є X but x K Show that there exist disjoint, open subsets of Gi and G2 of (X, d) such that r E Gi and KG2. (Hint: Use the version of compactness we called "having a compact topology." You will also need the Hausdorff property.) b) Now suppose that Ki and K2 are two compact, disjoint subsets of a metric space (X, d). Use (a)...
Exercise 5.3.2. [Used in Exercise 5.5.6.] Let [a,b] C R be a non-degenerate closed bounded interval, and let f: la,b] R be a function. Suppose that f is integrable Prove that if If(x)l S M for all xe la, b], for some M E R, then Jx)ds M(b-a)
Exercise 5.3.2. [Used in Exercise 5.5.6.] Let [a,b] C R be a non-degenerate closed bounded interval, and let f: la,b] R be a function. Suppose that f is integrable Prove that if...
Theorem 10.1.15 (Chain rule). Let X, Y be subsets of R, let xo e X be a limit point of X, and let yo e Y be a limit point of Y. Let f : X+Y be a function such that f(xo) = yo, and such that f is differentiable at Xo. Suppose that g:Y + R is a function which is differentiable at yo. Then the function gof:X + R is differentiable at xo, and .. (gºf)'(xo) = g'(yo)...
Question 6. a) Let A, B and C be open subsets of R. Prove that AnBn C is open. b) Give an example to show that the intersection of infinitely many open sets may not be open.