(1) Prove that if an upper triangular matrix A is invertible, then its inverse A-1 is also upper triangular and its diagonal entries are nonzero. Conversely, if an upper triangular matrix A has nonzero diagonal entries, then it is invertible. Furthermore, if the diagonal entries of A are positive, then so are the diagonal entries of A-1.

Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter5: Orthogonality
Section5.3: The Gram-schmidt Process And The Qr Factorization
Problem 23EQ
icon
Related questions
Question
(1) Prove that if an upper triangular matrix A is invertible, then its inverse A-1 is also upper
triangular and its diagonal entries are nonzero. Conversely, if an upper triangular matrix A
has nonzero diagonal entries, then it is invertible. Furthermore, if the diagonal entries of A
are positive, then so are the diagonal entries of A-1.
Transcribed Image Text:(1) Prove that if an upper triangular matrix A is invertible, then its inverse A-1 is also upper triangular and its diagonal entries are nonzero. Conversely, if an upper triangular matrix A has nonzero diagonal entries, then it is invertible. Furthermore, if the diagonal entries of A are positive, then so are the diagonal entries of A-1.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Knowledge Booster
Inverse of a Matrix
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
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Elementary Linear Algebra (MindTap Course List)
Elementary Linear Algebra (MindTap Course List)
Algebra
ISBN:
9781305658004
Author:
Ron Larson
Publisher:
Cengage Learning
Elements Of Modern Algebra
Elements Of Modern Algebra
Algebra
ISBN:
9781285463230
Author:
Gilbert, Linda, Jimmie
Publisher:
Cengage Learning,