/*! 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 6 Prove that if \(M \in M_{n \time... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Prove that if \(M \in M_{n \times n}(F)\) can be written in the form $$ M=\left(\begin{array}{ll} A & B \\ O & C \end{array}\right) $$ where \(A\) and \(C\) are square matrices, then \(\operatorname{det}(M)=\operatorname{det}(A) \cdot \operatorname{det}(C)\). Visit goo.g1/pgMdpX for a solution.

Short Answer

Expert verified
To prove the statement for the given matrix \( M =\left(\begin{array}{ll} A & B \\\ O & C \end{array}\right) \), we expanded the determinant using the first row or column, utilizing the properties of determinants and the zero matrix O. This ultimately led us to the simplified expression \( \operatorname{det}(M) = \operatorname{det}(A) \cdot \operatorname{det}(C) \), proving the given statement.

Step by step solution

01

Understanding the matrix structure

We are given a matrix M, which is in the block matrix form: \( M =\left(\begin{array}{ll} A & B \\\ O & C \end{array}\right) \) where M is of size n x n, A and C are square matrices, B is a rectangular matrix, and O is a zero matrix of appropriate size.
02

Finding the determinant of M

To find the determinant of M, we will use the properties of determinants. Since O is a zero matrix, we can expand the determinant using the first row or column to obtain: \( \operatorname{det}(M) = \operatorname{det}(A) \cdot \operatorname{det}(C) + \sum_{i=1}^{n}\sum_{j=1}^{n}m_{ij}\operatorname{det}(M_{ij}) \) Here, the sum represents the other elements of the matrix M and their corresponding minor determinants. Since the minor determinants corresponding to block O are zero, this expression simplifies to: \( \operatorname{det}(M) = \operatorname{det}(A) \cdot \operatorname{det}(C) \).
03

Conclusion

We have shown that for a matrix M in block form: \( M=\left(\begin{array}{ll} A & B \\\ O & C \end{array}\right) \), the determinant of M is equal to the product of the determinants of A and C: \( \operatorname{det}(M) = \operatorname{det}(A) \cdot \operatorname{det}(C) \). Hence, the given statement is proved.

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 \(y_{1}, y_{2}, \ldots, y_{n}\) be linearly independent functions in \(C^{\infty}\). For each \(y \in \mathrm{C}^{\infty}\), define $\mathrm{T}(y) \in \mathrm{C}^{\infty}$ by $$ [\mathrm{T}(y)](t)=\operatorname{det}\left(\begin{array}{ccccc} y(t) & y_{1}(t) & y_{2}(t) & \cdots & y_{n}(t) \\ y^{\prime}(t) & y_{1}^{\prime}(t) & y_{2}^{\prime}(t) & \cdots & y_{n}^{\prime}(t) \\ \vdots & \vdots & \vdots & & \vdots \\ y^{(n)}(t) & y_{1}^{(n)}(t) & y_{2}^{(n)}(t) & \cdots & y_{n}^{(n)}(t) \end{array}\right) . $$ The preceding determinant is called the Wronskian of $y, y_{1}, \ldots, y_{n}$. (a) Prove that $\mathrm{T}: \mathrm{C}^{\infty} \rightarrow \mathrm{C}^{\infty}$ is a linear transformation. (b) Prove that \(\mathbf{N}(\mathbf{T})\) contains span $\left(\left\\{y_{1}, y_{2}, \ldots, y_{n}\right\\}\right)$.

In Exercises 13-22, evaluate the determinant of the given matrix by any legitimate method. $$ \left(\begin{array}{lll} 0 & 0 & 1 \\ 0 & 2 & 3 \\ 4 & 5 & 6 \end{array}\right) $$

Suppose that \(U\) and \(W\) are subspaces of a vector space \(V\) and that \(S=\left\\{u_{i}\right\\}\) spans \(U\) and \(S^{\prime}=\left\\{w_{j}\right\\}\) spans \(W .\) Show that \(S \cup S^{\prime}\) spans \(U+W .\) (Accordingly, by induction, if \(S_{i}\) spans \(W_{i},\) for \(i=1,2, \ldots, n,\) then \(S_{1} \cup \ldots \cup S_{n}\) spans \(W_{1}+\cdots+W_{n}\)).

Prove that \(\operatorname{span}(S)\) is the intersection of all subspaces of \(V\) containing \(S\).

Let \(V\) be the vector space of \(n\) -square matrices. Let \(U\) be the subspace of upper triangular matrices, and let \(W\) be the subspace of lower triangular matrices. Find (a) \(U \cap W\), (b) \(U+W\).

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.