Question

Let f be a function from S to T and g be a function from T...

Let f be a function from S to T and g be a function from T to U.

Show the following:

  1. If f and g are injective, then their composition from S to U is injective
  2. If f and g are surjective, then their composition  from S to U is surjective
  3. If f and g are bijective, then their composition  from S to U is bijective

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
8.4: Let f : X → Y and g : Y→ Z be maps. Prove that...
8.4: Let f : X → Y and g : Y→ Z be maps. Prove that if composition g o f is surjective then g is surjective. 8.5: Let f : X → Y and g : Y→ Z be bijections. Prove that if composition g o f is bijective then f is bijective. 8.6: Let f : X → Y and g : Y→ Z be maps. Prove that if composition g o f is bijective then f is...
Let X, Y and Z be sets. Let f : X → Y and g :...
Let X, Y and Z be sets. Let f : X → Y and g : Y → Z functions. (a) (3 Pts.) Show that if g ◦ f is an injective function, then f is an injective function. (b) (2 Pts.) Find examples of sets X, Y and Z and functions f : X → Y and g : Y → Z such that g ◦ f is injective but g is not injective. (c) (3 Pts.) Show that...
Let f : A → B and g : B → C. For each statement below...
Let f : A → B and g : B → C. For each statement below either prove it or construct f, g, A, B, C which show that the statement is false. (a) If g ◦ f is surjective, then g is surjective. (b) If g ◦ f is surjective, then f is surjective. (c) If g ◦ f is injective, then f and g are injective
Part II True or false: a. A surjective function defined in a finite set X over...
Part II True or false: a. A surjective function defined in a finite set X over the same set X is also BIJECTIVE. b. All surjective functions are also injective functions c. The relation R = {(a, a), (e, e), (i, i), (o, o), (u, u)} is a function of V in V if V = {a, e, i, o, u}. d. The relation in which each student is assigned their age is a function. e. A bijective function defined...
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.
Is the function f : R → R defined by f(x) = x 3 − x...
Is the function f : R → R defined by f(x) = x 3 − x injective, surjective, bijective or none of these? Thank you!
For an abelian group G, let tG = {x E G: x has finite order} denote...
For an abelian group G, let tG = {x E G: x has finite order} denote its torsion subgroup. Show that t defines a functor Ab -> Ab if one defines t(f) = f|tG (f restricted on tG) for every homomorphism f. If f is injective, then t(f) is injective. Give an example of a surjective homomorphism f for which t(f) is not surjective.
Consider the cubic function f: x^3 -10x^2 - 123x + 432 a) Sketch the graph of...
Consider the cubic function f: x^3 -10x^2 - 123x + 432 a) Sketch the graph of f. b) Identify the domain and co-domain in which f is NOT Injective and NOT surjective. Briefly explain c) Identify the domain and co-domain in which f is Injective but NOT Surjective. Briefly explain d) Identify the domain and co-domain in which f is Surjective but NOT Injective. Briefly explain e). Identify the domain and co-domain in which f is Bijective. Explain briefly
Let S = {A, B, C, D, E, F, G, H, I, J} be the set...
Let S = {A, B, C, D, E, F, G, H, I, J} be the set consisting of the following elements: A = N, B = 2N , C = 2P(N) , D = [0, 1), E = ∅, F = Z × Z, G = {x ∈ N|x 2 + x < 2}, H = { 2 n 3 k |n, k ∈ N}, I = R \ Q, J = R. Consider the relation ∼ on S given...
Let f : R → R + be defined by the formula f(x) = 10^2−x ....
Let f : R → R + be defined by the formula f(x) = 10^2−x . Show that f is injective and surjective, and find the formula for f −1 (x). Suppose f : A → B and g : B → A. Prove that if f is injective and f ◦ g = iB, then g = f −1 .