Given w =< W1,W2, W3 > Prove or disapprove: w · w = ||w||. Explain all detail-

Algebra and Trigonometry (6th Edition)
6th Edition
ISBN:9780134463216
Author:Robert F. Blitzer
Publisher:Robert F. Blitzer
ChapterP: Prerequisites: Fundamental Concepts Of Algebra
Section: Chapter Questions
Problem 1MCCP: In Exercises 1-25, simplify the given expression or perform the indicated operation (and simplify,...
icon
Related questions
Topic Video
Question

Prove or disapprove:

### Problem Statement

**Given**: \( \mathbf{w} = \langle w_1, w_2, w_3 \rangle \)

**Prove or disapprove**: \( \mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2 \).

**Task**: Explain all details.

### Explanation

To address the problem, we need to understand the meanings of both dot product and vector norm:

1. **Dot Product** (\(\mathbf{w} \cdot \mathbf{w}\)):
   - The dot product of a vector with itself is calculated by multiplying each of its components by itself and then summing the results:
   \[
   \mathbf{w} \cdot \mathbf{w} = w_1^2 + w_2^2 + w_3^2
   \]

2. **Norm of a Vector** (\(\|\mathbf{w}\|\)):
   - The norm (or magnitude) of a vector is calculated as the square root of the sum of the squares of its components:
   \[
   \|\mathbf{w}\| = \sqrt{w_1^2 + w_2^2 + w_3^2}
   \]

3. **Square of the Norm** (\(\|\mathbf{w}\|^2\)):
   - Taking the square of the vector norm cancels out the square root:
   \[
   \|\mathbf{w}\|^2 = (\sqrt{w_1^2 + w_2^2 + w_3^2})^2 = w_1^2 + w_2^2 + w_3^2
   \]

From the above calculations, it is evident that:
\[
\mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2
\]

### Conclusion

The statement \( \mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2 \) is indeed true. The dot product of a vector with itself is equal to the square of its norm.
Transcribed Image Text:### Problem Statement **Given**: \( \mathbf{w} = \langle w_1, w_2, w_3 \rangle \) **Prove or disapprove**: \( \mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2 \). **Task**: Explain all details. ### Explanation To address the problem, we need to understand the meanings of both dot product and vector norm: 1. **Dot Product** (\(\mathbf{w} \cdot \mathbf{w}\)): - The dot product of a vector with itself is calculated by multiplying each of its components by itself and then summing the results: \[ \mathbf{w} \cdot \mathbf{w} = w_1^2 + w_2^2 + w_3^2 \] 2. **Norm of a Vector** (\(\|\mathbf{w}\|\)): - The norm (or magnitude) of a vector is calculated as the square root of the sum of the squares of its components: \[ \|\mathbf{w}\| = \sqrt{w_1^2 + w_2^2 + w_3^2} \] 3. **Square of the Norm** (\(\|\mathbf{w}\|^2\)): - Taking the square of the vector norm cancels out the square root: \[ \|\mathbf{w}\|^2 = (\sqrt{w_1^2 + w_2^2 + w_3^2})^2 = w_1^2 + w_2^2 + w_3^2 \] From the above calculations, it is evident that: \[ \mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2 \] ### Conclusion The statement \( \mathbf{w} \cdot \mathbf{w} = \|\mathbf{w}\|^2 \) is indeed true. The dot product of a vector with itself is equal to the square of its norm.
Expert 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, algebra and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Algebra and Trigonometry (6th Edition)
Algebra and Trigonometry (6th Edition)
Algebra
ISBN:
9780134463216
Author:
Robert F. Blitzer
Publisher:
PEARSON
Contemporary Abstract Algebra
Contemporary Abstract Algebra
Algebra
ISBN:
9781305657960
Author:
Joseph Gallian
Publisher:
Cengage Learning
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Algebra And Trigonometry (11th Edition)
Algebra And Trigonometry (11th Edition)
Algebra
ISBN:
9780135163078
Author:
Michael Sullivan
Publisher:
PEARSON
Introduction to Linear Algebra, Fifth Edition
Introduction to Linear Algebra, Fifth Edition
Algebra
ISBN:
9780980232776
Author:
Gilbert Strang
Publisher:
Wellesley-Cambridge Press
College Algebra (Collegiate Math)
College Algebra (Collegiate Math)
Algebra
ISBN:
9780077836344
Author:
Julie Miller, Donna Gerken
Publisher:
McGraw-Hill Education