Let f : A → B be a function. Prove the following: (a) If f is injective, then f is surjective. (b) If ƒ is surjective, f then is injective.

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

Definition in next picture

Let f : A → B be a function. Prove the following:
(a) If f is injective, then f is surjective.
(b) If f is surjective, f then is injective.
Transcribed Image Text:Let f : A → B be a function. Prove the following: (a) If f is injective, then f is surjective. (b) If f is surjective, f then is injective.
Let f: A→ B be a function. If D is any subset of B, the inverse image of D
under f, which we write f (D), is the following subset of A:
Š (D) = {r € A|f (x) E D} .
%3D
That is, f (D) is the set of all the pre-images of the elements of D.
Transcribed Image Text:Let f: A→ B be a function. If D is any subset of B, the inverse image of D under f, which we write f (D), is the following subset of A: Š (D) = {r € A|f (x) E D} . %3D That is, f (D) is the set of all the pre-images of the elements of D.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

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,