/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 49 Determine whether the statement ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Determine whether the statement is true or false. If it is true, explain why it is true. If it is false, give an example to show why it is false. If \(A^{-1}\) does not exist, then the system \(A X=B\) of \(n\) linear equations in \(n\) unknowns does not have a unique solution.

Short Answer

Expert verified
The statement is true. If \(A^{-1}\) does not exist, then the system AX = B does not have a unique solution. This is because the system can either have no solution (inconsistent system) or infinitely many solutions (dependent equations with a free variable). In both cases, a unique solution is not possible when the inverse of A does not exist.

Step by step solution

01

Determine Invertibility of A

The first part of the statement deals with the inverse of matrix A. The inverse of a matrix A exists if it is a square matrix (i.e., it has the same number of rows and columns) and its determinant is non-zero. A matrix with no inverse is called a singular matrix. In this exercise, we are given that \(A^{-1}\) does not exist.
02

Effects of non-existent inverse on the solution of AX = B

The existence of an inverse has a significant impact on the solution of a system of linear equations, AX = B. If there exists a unique solution of AX = B, then it can be found by left-multiplying both sides of the equation with the inverse of A such that \(A^{-1} (A X) = A^{-1} B\) or simply X = \(A^{-1} B\). Since \(A^{-1}\) does not exist, we cannot use this method to find the unique solution of AX = B. The system AX = B can have either no solution or infinitely many solutions depending on the setup of the linear system.
03

Provide Explanation or Counterexample

According to the given statement, we need to show that if \(A^{-1}\) does not exist, then the system AX = B does not have a unique solution. This statement is true. Explanation: Let's consider two possibilities for a system of linear equations without a unique solution - no solutions or infinitely many solutions. 1. No solution: This occurs when the system of linear equations is inconsistent, which means that the rows of the augmented matrix ([A|B]) represent contradictory equations. In this case, the system cannot have a unique solution. 2. Infinitely many solutions: This occurs when the system of linear equations has dependent equations, and one or more variables can take any values. It means there is a free variable in the echelon form of the coefficient matrix. In this case, the system cannot have a unique solution. Since we have shown that AX = B either has no solution or infinitely many solutions if \(A^{-1}\) does not exist, the statement is considered true.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Let $$ A=\left[\begin{array}{rr} 2 & 3 \\ -4 & -5 \end{array}\right] $$ a. Find \(A^{-1}\). b. Show that \(\left(A^{-1}\right)^{-1}=A\).

Determine whether the statement is true or false. If it is true, explain why it is true. If it is false, give an example to show why it is false. If \(A, B\), and \(C\) are matrices and \(A(B+C)\) is defined, then \(B\) must have the same size as \(C\) and the number of columns of \(A\) must be equal to the number of rows of \(B\).

Let \(A=\left[\begin{array}{ll}2 & -5 \\ 1 & -3\end{array}\right] \quad B=\left[\begin{array}{ll}4 & 3 \\ 1 & 1\end{array}\right] \quad C=\left[\begin{array}{rr}2 & 3 \\ -2 & 1\end{array}\right]\) a. Find \(A B C, A^{-1}, B^{-1}\), and \(C^{-1}\). b. Show that \((A B C)^{-1}=C^{-1} B^{-1} A^{-1}\).

Mr. Cross. Mr. Jones, and Mr. Smith each suffer from coronary heart disease. As part of their treatment, they were put on special low-cholesterol diets: Cross on diet I, Jones on diet II, and Smith on diet III. Progressive records of each patient's cholesterol level were kept. At the beginning of the first, second, third, and fourth months, the cholesterol levels of the three patients were: Cross: \(220,215,210\), and 205 Jones: \(220,210,200\), and 195 Smith: \(215,205,195\), and 190 Represent this information in a \(3 \times 4\) matrix.

The problems in exercise correspond to those in exercises 15-27, Section 2.1. Use the results of your previous work to help you solve these problems. The management of Hartman Rent-A-Car has allocated $$\$ 1.5$$ million to buy a fleet of new automobiles consisting of compact, intermediate-size, and full- size cars. Compacts cost $$\$ 12,000$$ each, intermediatesize cars cost $$\$ 18,000$$ each, and full-size cars cost $$\$ 24,000$$ each. If Hartman purchases twice as many compacts as intermediate-size cars and the total number of cars to be purchased is 100 , determine how many cars of each type will be purchased. (Assume that the entire budget will be used.)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.