Math Problem Statement

Let A be a set with A = {1, 2, 3} and let R be a binary relation on A defined by R = {(a,b) ∈ A | a ≤ b}. Which one of the following matrices represents the relation R?

Solution

Let's break down the question step by step.

We have a set A={1,2,3}A = \{1, 2, 3\}, and a binary relation RR on AA, defined as:

R={(a,b)A×Aab}R = \{ (a, b) \in A \times A \mid a \leq b \}

This means the relation includes all pairs where the first element aa is less than or equal to the second element bb.

We need to determine which of the matrices represents this relation.

Steps to find the correct matrix:

  1. We will represent each element of the set A={1,2,3}A = \{1, 2, 3\} by its index in a matrix, i.e., 11 is represented by the first row/column, 22 by the second row/column, and 33 by the third row/column.
  2. For each pair (a,b)(a, b), we set the entry in the matrix to 1 if aba \leq b, otherwise 0.
    • Row 1 corresponds to a=1a = 1, and it should have 1's in columns where 1b1 \leq b, i.e., columns for b=1,2,3b = 1, 2, 3.
    • Row 2 corresponds to a=2a = 2, and it should have 1's in columns where 2b2 \leq b, i.e., columns for b=2,3b = 2, 3.
    • Row 3 corresponds to a=3a = 3, and it should have 1's in columns where 3b3 \leq b, i.e., columns for b=3b = 3.

Let's now check the provided options. Based on this reasoning, I'll determine which matrix corresponds to the relation RR. Let me check the image for details. PIL import Image

Open the uploaded image to analyze its contents

img_path = '/mnt/data/1738902298976fb8iijz4.jpg' img = Image.open(img_path) img.show()I have opened the image. Now I will analyze the matrices and their corresponding relationships based on the criteria we discussed. Based on the set A={1,2,3}A = \{1, 2, 3\} and the relation R={(a,b)ab}R = \{(a, b) \mid a \leq b\}, let's check which of the matrices matches this relation.

Given the conditions for each row in the matrix based on aba \leq b, here is the correct pattern:

  • Row 1: Since 11,12,131 \leq 1, 1 \leq 2, 1 \leq 3, all entries in row 1 should be 1.
  • Row 2: Since 22,232 \leq 2, 2 \leq 3, entries in row 2 for columns 2 and 3 should be 1.
  • Row 3: Since 333 \leq 3, only the entry in row 3, column 3 should be 1.

This leads to the correct matrix:

1 & 1 & 1 \\ 0 & 1 & 1 \\ 0 & 0 & 1 \end{bmatrix}$$ Now, I'll check which option matches this structure from the given choices.After reviewing the matrices in the image, the correct one that matches the relation $$R = \{ (a, b) \mid a \leq b \}$$ is the second matrix: $$\begin{bmatrix} 1 & 1 & 1 \\ 0 & 1 & 1 \\ 0 & 0 & 1 \end{bmatrix}$$ This matrix satisfies the condition where the relation includes all pairs $$(a, b)$$ where $$a \leq b$$. Would you like to go into more detail on any of the steps, or do you have further questions? Here are some related questions for exploration: 1. How do binary relations work in other contexts (e.g., reflexivity, symmetry)? 2. Can the relation $$R$$ be visualized as a graph? If so, how would that look? 3. What is the difference between a binary relation and a function in set theory? 4. How can you define other types of binary relations (e.g., transitive, anti-symmetric)? 5. What are the properties of matrices representing binary relations? **Tip**: To visualize binary relations, try plotting the pairs $$(a, b)$$ on a coordinate system, where each pair represents a point or connection. This can help clarify concepts like reflexivity and transitivity.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Binary Relations
Matrices
Set Theory

Formulas

Matrix Representation of Relations

Theorems

Reflexivity and Order Relations

Suitable Grade Level

Undergraduate / High School Advanced Mathematics