Simple Function: Difference between revisions

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==Definition==
==Definition==
Let <math> (X, \mathcal{M}, \mu) </math> be a measure space. A [[Measurable function | measurable function]] <math>f: X \rightarrow \mathbb{R}</math> is a simple function if <math>f(X)</math> is a finite subset of <math> \mathbb{R}</math>. <ref name="Craig">Craig, Katy. ''MATH 201A Lecture 11''. UC Santa Barbara, Fall 2020.</ref> The standard representation for a simple function is given by  
Let <math> (X, \mathcal{M}, \mu) </math> be a measure space. A [[Measurable function | measurable function]] <math>f: X \rightarrow \mathbb{R}</math> is a simple function<ref name="Craig">Craig, Katy. ''MATH 201A Lecture 11''. UC Santa Barbara, Fall 2020.</ref> if <math>f(X)</math> is a finite subset of <math> \mathbb{R}</math>. The standard representation for a simple function is given by  


<math> f(x) = \sum_{i=1}^n c_i 1_{E_i} (x) </math>,
<math> f(x) = \sum_{i=1}^n c_i 1_{E_i} (x) </math>,

Revision as of 00:08, 10 December 2020

The simplest functions you will ever integrate, hence the name.

Definition

Let be a measure space. A measurable function is a simple function[1] if is a finite subset of . The standard representation for a simple function is given by

,

where is the indicator function on the disjoint set where .

[2]

Properties of Simple Functions

Integration of Simple Functions

References

  1. Craig, Katy. MATH 201A Lecture 11. UC Santa Barbara, Fall 2020.
  2. Folland, Gerald B. (1999). Real Analysis: Modern Techniques and Their Applications, John Wiley and Sons, ISBN 0471317160, Second edition.