2. Let f : A ! B. DeÖne a relation R on A by xRy i§ f (x) = f (y). a. Prove that R is an equivalence relation on A. b. Let Ex = fy 2 A : xRyg be the equivalence class of x 2 A. DeÖne E = fEx : x 2 Ag to be the collection of all equivalence classes. Prove that the function g : A ! E deÖned by g (x) = Ex is...
(1) Let X and Y be sets. Let f be a function from X to Y, (a) IF BEY, recall that F-'(B) = {xeX \flyeBX(y,x) ef-)}. Prove that f'(B)={xeX | fk)e B}. (hint: Reprember that even though t is a thought is a function, the relation f may well not be itself a function.) Al b) Let {B; \je J} be an inbred family of subsets of Y. Prove that of "b) = f'(21B;).
Theorem 7.3.5 Let P be a partition of a nonempty set X. Define a relation~on X for all a, b X by defining: Then is an equivalence relation on X. Furthermore, the equivalence classes ofare exactly the elements of the partition P: that is, X/ ~= P. Proof: See page 164 in your textbook. a,b,c,d,e,f partition P = {{a, c, e), {b, f}, {d)) 5 Let A = Give a complete listing of the ordered pairs in the equivalence relation...
l maps is a quotient map. 4, Let ( X,T ) be a topological space, let Y be a nonempty set, let f be a function that maps X onto Y, let U be the quotient topology on induced by f, and let (Z, V) be a topological space. Prove that a function g:Y Z is continuous if and only if go f XZ is continuous. l maps is a quotient map. 4, Let ( X,T ) be a topological...
For nonempty sets A, B and C, let f : A → B and g : B → C be functions. Prove that if g ◦ f is injective, then f is injective
Problem 11.9. For two nonempty disjoint sets, and J, let A : E/} be a parti- tion ofR" and Ag' α E J} be a partition of R-u0). Prove that(Aq : α Ε 1w} is a partition of R. Problem 11.9. For two nonempty disjoint sets, and J, let A : E/} be a parti- tion ofR" and Ag' α E J} be a partition of R-u0). Prove that(Aq : α Ε 1w} is a partition of R.
2. Consider the relation E on Z defined by E n, m) n+ m is even} equivalence relation (a) Prove that E is an (b) Let n E Z. Find [n]. equivalence relation in [N, the equivalence class of 3. We defined a relation on sets A B. Prove that this relation is an (In this view, countable sets the natural numbers under this equivalence relation). exactly those that are are 2. Consider the relation E on Z defined by...
Let R be the relation on N defined by xRy iff 2 divides x+y. R is an equivalence relation. You do not have to prove that R is an equivalence relation. True or False: 3 ∈ 4/R.
Let T be the relation defined on R given by T = {(x,y)|X, Y E RAx-yeZ}. a. Prove T is an equivalence relation. b. Prove Ō =Z c. Find 1.5
·J (I) < 0 for all such y. (Hint: let g(x)--f(x) and use part (a)) 3. In this problem, we prove the Intermedinte Value Theorem. Let Intermediate Value Theorem. Let f : [a → R be continuous, and suppose f(a) < 0 and f(b) >0. Define S = {t E [a, b] : f(z) < 0 for allェE [a,t)) (a) Prove that s is nonempty and bounded above. Deduce that c= sup S exists, and that astst (b) Use Problem...