Definition. Let X and Y be topological spaces. A function or map f : X continuous function or continuous map if and only if for every open set U in Y, f-'(U) is open in X. → Y is a Theorem 7.1. Let X and Y be topological spaces, and let f : X → Y be a function. Then the following are equivalent: (1) The function f is continuous. (2) For every closed set K in Y, the inverse image f-!(K) is closed in X. (3) For every limit point p of a set A in X, the image f(p) belongs to f(A). (4) For every x E X and open set V containing f(x), there is an open set U containing x such that f(U) C V. Theorem 7.2. Let X,Y be topological spaces and yo E Y. The constant map f :X → Y defined by f(x) = yo is continuous. Theorem 7.3. Let X c Y be topological spaces. The inclusion map i : X → Y defined by i(x) — х is continиоus. Y be a continuous map between topological spaces, and let A be a subset of X. Then the restriction map f\a : A → Y defined by f\a(a) = f(a) is Theorem 7.4. Let f : X → continuous.

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
Topic Video
Question
100%

Could you explain how to show 7.4 in detail?

Definition. Let X and Y be topological spaces. A function or map f : X –→ Y is a
continuous function or continuous map if and only if for every open set U in Y,
f-'(U) is open in X.
Theorem 7.1. Let X and Y be topological spaces, and let f : X
the following are equivalent:
Y be a function. Then
(1) The function f is continuous.
(2) For every closed set K in Y, the inverse image f-1(K) is closed in X.
(3) For every limit point p of a set A in X, the image f(p) belongs to f(A).
(4) For every x E X and open set V containing f(x), there is an open set U containing x
such that f(U) V.
Theorem 7.2. Let X,Y be topological spaces and yo E Y. The constant map f :X → Y
defined by f(x) = yo is continuous.
Theorem 7.3. Let X c Y be topological spaces. The inclusion map i : X → Y defined
by i(x) — х is сontinuous.
Theorem 7.4. Let f : X
A be a subset of X. Then the restriction map f\a : A → Y defined by f\a(a) = f(a) is
Y be a continuous map between topological spaces, and let
сontinuous.
Transcribed Image Text:Definition. Let X and Y be topological spaces. A function or map f : X –→ Y is a continuous function or continuous map if and only if for every open set U in Y, f-'(U) is open in X. Theorem 7.1. Let X and Y be topological spaces, and let f : X the following are equivalent: Y be a function. Then (1) The function f is continuous. (2) For every closed set K in Y, the inverse image f-1(K) is closed in X. (3) For every limit point p of a set A in X, the image f(p) belongs to f(A). (4) For every x E X and open set V containing f(x), there is an open set U containing x such that f(U) V. Theorem 7.2. Let X,Y be topological spaces and yo E Y. The constant map f :X → Y defined by f(x) = yo is continuous. Theorem 7.3. Let X c Y be topological spaces. The inclusion map i : X → Y defined by i(x) — х is сontinuous. Theorem 7.4. Let f : X A be a subset of X. Then the restriction map f\a : A → Y defined by f\a(a) = f(a) is Y be a continuous map between topological spaces, and let сontinuous.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

Blurred answer
Knowledge Booster
Propositional Calculus
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, advanced-math and related others by exploring similar questions and additional content below.
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,