Question

Suppose that f is a bijection and f ∘ g is defined. Prove: (i). g is...

Suppose that f is a bijection and f ∘ g is defined. Prove:

(i). g is an injection iff f ∘ g is;

(ii). g is a surjection iff f ∘ g is.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Is f(x) = x^3 - x an injection, surjection, or bijection? How do I know?
Is f(x) = x^3 - x an injection, surjection, or bijection? How do I know?
Prove or disprove: If f:A→B and g:B→A are functions and g◦f is a bijection, then f...
Prove or disprove: If f:A→B and g:B→A are functions and g◦f is a bijection, then f and g are bijections.
3. Let N denote the nonnegative integers, and Z denote the integers. Define the function g...
3. Let N denote the nonnegative integers, and Z denote the integers. Define the function g : N→Z defined by g(k) = k/2 for even k and g(k) = −(k + 1)/2 for odd k. Prove that g is a bijection. (a) Prove that g is a function. (b) Prove that g is an injection . (c) Prove that g is a surjection.
Let f:A→B and g:B→C be maps. Prove that if g◦f is a bijection, then f is...
Let f:A→B and g:B→C be maps. Prove that if g◦f is a bijection, then f is injective and g is surjective.*You may not use, without proof, the result that if g◦f is surjective then g is surjective, and if g◦f is injective then f is injective. In fact, doing so would result in circular logic.
Assume that X and Y are finite sets. Prove the following statement: If there is a...
Assume that X and Y are finite sets. Prove the following statement: If there is a bijection f:X→Y then|X|=|Y|. Hint: Show that if f : X → Y is a surjection then |X| ≥ |Y| and if f : X → Y is an injection then |X| ≤ |Y |.
Let n ∈ N and f : [n] → [n] a function. Prove that f is...
Let n ∈ N and f : [n] → [n] a function. Prove that f is a surjection if and only if f is an injection.
(2) Let f : A → A be a bijection. Suppose ∅ ⊂ S ⊆ A...
(2) Let f : A → A be a bijection. Suppose ∅ ⊂ S ⊆ A and f : S → S is also a bijection. Show that f is bijection f : (A − S) → (A − S).
Let f and g be functions between A and B. Prove that f = g iff...
Let f and g be functions between A and B. Prove that f = g iff the domain of f = the domain of g and for every x in the domain of f, f(x) = g(x). Thank you!
For each of the following, give an example of a function g and a function f...
For each of the following, give an example of a function g and a function f that satisfy the stated conditions. Or state that such an example cannot exist. Be sure to clearly state the domain and codomain for each function. (a)The function g is a surjection, but the function fog is not a surjection. (b) The function g is not an injection, but the function fog is an injection. (c)The function g is an injection, but the function fog...
(a) Suppose f and g are di?erentiable on an interval I and that f(x) − ((g(x))n...
(a) Suppose f and g are di?erentiable on an interval I and that f(x) − ((g(x))n = c for all xεI (where nεNand cεR are constants). If g(x) ̸= 0 on I, then g′(x) = −f(x)((g(x))1−n.n (b) If f is not di?erentiable at x0,then f is not continuous at x0. (c) Suppose f and g are di?erentiable on an interval I and suppose that f′(x) = g′(x)on I. Then f(x) = g(x) on I. (d) The equation of the line...