Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter5: Orthogonality
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

Downvoting if all parts aren't andered

A square matrix A is idempotent if A² = A.
Let V be the vector space of all 2 × 2 matrices with real entries. Let H be the set of all
2 x 2 idempotent matrices with real entries. Is H a subspace of the vector space V?
1. Does H contain the zero vector of V?
choose
2. Is H closed under addition? If it is, enter CLOSED. If it is not, enter two
matrices in H whose sum is not in H, using a comma separated list and syntax
such as [[1,2], [3,4]], [[5,6], [7,8]] for the answer
[12] [5
3 4
to show that H is not closed under addition, it is sufficient to find two
idempotent matrices A and B such that (A + B)² + (A+B).)
8
(Hint:
3. Is H closed under scalar multiplication? If it is, enter CLOSED. If it is not, enter
a scalar in R and a matrix in H whose product is not in H, using a comma
[34]
separated list and syntax such as 2, [[3,4], [5,6]] for the answer 2, 5 6
(Hint: to show that H is not closed under scalar multiplication, it is sufficient to
find a real number r and an idempotent matrix A such that (rA)² + (rA).)
4. Is H a subspace of the vector space V? You should be able to justify your answer
by writing a complete, coherent, and detailed proof based on your answers to
parts 1-3.
choose
Transcribed Image Text:A square matrix A is idempotent if A² = A. Let V be the vector space of all 2 × 2 matrices with real entries. Let H be the set of all 2 x 2 idempotent matrices with real entries. Is H a subspace of the vector space V? 1. Does H contain the zero vector of V? choose 2. Is H closed under addition? If it is, enter CLOSED. If it is not, enter two matrices in H whose sum is not in H, using a comma separated list and syntax such as [[1,2], [3,4]], [[5,6], [7,8]] for the answer [12] [5 3 4 to show that H is not closed under addition, it is sufficient to find two idempotent matrices A and B such that (A + B)² + (A+B).) 8 (Hint: 3. Is H closed under scalar multiplication? If it is, enter CLOSED. If it is not, enter a scalar in R and a matrix in H whose product is not in H, using a comma [34] separated list and syntax such as 2, [[3,4], [5,6]] for the answer 2, 5 6 (Hint: to show that H is not closed under scalar multiplication, it is sufficient to find a real number r and an idempotent matrix A such that (rA)² + (rA).) 4. Is H a subspace of the vector space V? You should be able to justify your answer by writing a complete, coherent, and detailed proof based on your answers to parts 1-3. choose
Expert Solution
steps

Step by step

Solved in 3 steps with 2 images

Blurred answer