Question

Let matrices A,B∈Mn×n(R). Show that if A and B are each similar to some diagonal matrix,...

Let matrices A,B∈Mn×n(R). Show that if A and B are each similar to some diagonal matrix, and also have the same eigenvectors (but not necessarily the same eigenvalues), then  AB=BA.

Homework Answers

Answer #1

here the matrix have the same eign vectors but no necessarily the same eign values so we use the similaity reltaion , noting that both the matrix are diagonalizable , but there diagonal forms are different , since there eign values are different , but the diagonal forms commute , so we simply use these these facts , here I am giving the solution below,

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
We say two n × n matrices A and B are similar if there is an...
We say two n × n matrices A and B are similar if there is an invertible n × n matrix P such that A = PBP^ -1. a) Show that if A and B are similar n × n matrices, then they must have the same determinant. b) Show that if A and B are similar n × n matrices, then they must have the same eigenvalues. c) Give an example to show that A and B can be...
Let A, B ? Mn×n be invertible matrices. Prove the following statement: Matrix A is similar...
Let A, B ? Mn×n be invertible matrices. Prove the following statement: Matrix A is similar to B if and only if there exist matrices X, Y ? Mn×n so that A = XY and B = Y X.
Let A, B be n × n matrices. The following are two incorrect proofs that ABhas...
Let A, B be n × n matrices. The following are two incorrect proofs that ABhas the same non-zero eigenvalues as BA. For each, state two things wrong with the proof: (i) We will prove that AB and BA have the same characteristic equation. We have that det(AB − λI) = det(ABAA−1 − λAA−1) = det(A(BA − λI)A−1) = det(A) + det(BA − λI) − det(A) = det(BA − λI) Hence det(AB − λI) = det(BA − λI), and so...
I'm studying Linear Algebra. A Matrix A is a 3*3 matrix and it has 3 linear...
I'm studying Linear Algebra. A Matrix A is a 3*3 matrix and it has 3 linear independent eigenvectors. The Matrix B has the same eigenvectors (but not necessarily the same eigenvalues). I'm supposed to prove that AB=BA. I'm given a clue that says: ,, Is it possible to diagonal A and B?''. I want to be clear that the matrixes are not given. Thank you.
Let A be a (n × n) matrix. Show that A and AT have the same...
Let A be a (n × n) matrix. Show that A and AT have the same characteristic polynomials (and therefore the same eigenvalues). Hint: For any (n×n) matrix B, we have det(BT) = det(B). Remark: Note that, however, it is generally not the case that A and AT have the same eigenvectors!
n×n-matrix M is symmetric if M = M^t. Matrix M is anti-symmetric if M^t = -M....
n×n-matrix M is symmetric if M = M^t. Matrix M is anti-symmetric if M^t = -M. 1. Show that the diagonal of an anti-symmetric matrix are zero 2. suppose that A,B are symmetric n × n-matrices. Prove that AB is symmetric if AB = BA. 3. Let A be any n×n-matrix. Prove that A+A^t is symmetric and A - A^t antisymmetric. 4. Prove that every n × n-matrix can be written as the sum of a symmetric and anti-symmetric matrix.
For an n×n matrix, A, the trace of A is defined as the sum of the...
For an n×n matrix, A, the trace of A is defined as the sum of the entries on the main diagonal. That is, tr(A)=a11+a22+?+ann. (a) Prove that for any matrices A and B having the same size, tr(A+B)=tr(A)+tr(B) and for any scalar c, tr(cA)=ctr(A) (b) Prove tr(A)=tr(AT) for all square matrices A. (c) Prove that for any matrices A and B having the same size, tr(AB)=tr(BA). (d) Using (c), prove that if A and B are similar tr(A)=tr(B).
Let A,B be nxn real matrices. Show that AB and BA have the same characteristic polynomial.
Let A,B be nxn real matrices. Show that AB and BA have the same characteristic polynomial.
Prove the following statements: a) If A and B are two positive semidefinite matrices in IR...
Prove the following statements: a) If A and B are two positive semidefinite matrices in IR ^ n × n , then trace (AB) ≥ 0. If, in addition, trace (AB) = 0, then AB = BA =0 b) Let A and B be two (different) n × n real matrices such that R(A) = R(B), where R(·) denotes the range of a matrix. (1) Show that R(A + B) is a subspace of R(A). (2) Is it always true...
Suppose A and B are invertible matrices in Mn(R) and that A + B is also...
Suppose A and B are invertible matrices in Mn(R) and that A + B is also invertible. Show that C = A-1 + B-1 is also invertible.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT