Let A, B, C be nonempty sets and let f : AB, g: B → C be functions such that go f is bijective. Prove that g is injective if and only if f is surjective.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question
**Mathematical Problem: Injective and Surjective Functions**

**Problem Statement:**

Let \( A, B, C \) be nonempty sets and let \( f: A \to B \), \( g: B \to C \) be functions such that the composition \( g \circ f \) is bijective. Prove that \( g \) is injective if and only if \( f \) is surjective.

**Explanation:**

The problem explores the conditions under which the composition of two functions is both injective (one-to-one) and surjective (onto), thereby making it bijective. It focuses on:

- **Surjectivity (Onto):** Every element of the set \( B \) is an image of at least one element from the set \( A \).
- **Injectivity (One-to-One):** Each element of the set \( B \) is mapped to a unique element in \( A \).
- **Bijectivity:** A function that is both injective and surjective.

The aim is to demonstrate a relationship between the injectivity of \( g \) and the surjectivity of \( f \) given that their composition \( g \circ f \) is bijective.
Transcribed Image Text:**Mathematical Problem: Injective and Surjective Functions** **Problem Statement:** Let \( A, B, C \) be nonempty sets and let \( f: A \to B \), \( g: B \to C \) be functions such that the composition \( g \circ f \) is bijective. Prove that \( g \) is injective if and only if \( f \) is surjective. **Explanation:** The problem explores the conditions under which the composition of two functions is both injective (one-to-one) and surjective (onto), thereby making it bijective. It focuses on: - **Surjectivity (Onto):** Every element of the set \( B \) is an image of at least one element from the set \( A \). - **Injectivity (One-to-One):** Each element of the set \( B \) is mapped to a unique element in \( A \). - **Bijectivity:** A function that is both injective and surjective. The aim is to demonstrate a relationship between the injectivity of \( g \) and the surjectivity of \( f \) given that their composition \( g \circ f \) is bijective.
Expert Solution
steps

Step by step

Solved in 4 steps with 3 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,