Let A = Construct a 4x2 matrix D, using only 1 and 0 as entries, such that AD = I2. Is it possible that CA =I4 for some 4X2 matrix C? Explain.
Is it possible that CA = I4 for some 4 x 2 matrix C? Explain. Choose the correct answer below.
A. No, because neither C nor A are invertible. When writing lm as the product of two matrices, since lm is invertible, those two matrices will also be invertible.
B. Yes, because C is a 4 x2 matrix and A is a 2 x4 matrix, making CA a 4x4 matrix. For every mxn matrix, there exists an nxm matrix such that the product of the two matrices is lm
C. No, because if it were true, then CAx would equal x for all x in R4. Since the columns of A are linearly dependent, Ax=0 for some nonzero vector x. For such an x, x= Ix = CAx = 0, a contradiction. Hence, CA cannot equal lm.
D. Yes, if C=AT. The product of any mxn matrix and its transpose is lm
Let U and V be nxn orthogonal matrices. Explain why UV is an orthogonal matrix. [That is, explain why UV is invertible and its inverse is (UV)'.] Why is UV invertible? O A. Since U and V are nxn matrices, each is invertible by the definition of invertible matrices. The product of two invertible matrices is also invertible. OB. UV is invertible because it is an orthogonal matrix, and all orthogonal matrices are invertible. O c. Since U and V...
a) Let I be the n x n identity matrix and let O be the n × n zero matrix . Suppose A is an n × n matrix such that A3 = 0. Show that I + A is invertible and that (I + A)-1 = I – A+ A2. b) Let B and C be n x n matrices. Assume that the product BC is invertible. Show that B and C are both invertible.
Problem 1. Let A be an m x m matrix. (a) Prove by induction that if A is invertible, then for every n N, An is invertible. (b) Prove that if there exists n N such that An is invertible, then A is invertible. (c) Let Ai, . . . , An be m x m matrices. Prove that if the product Ai … An is an invertible matrix, then Ak is invertible for each 1 < k< n. (d)...
2. (a) (10 marks) Suppose A is an n x n real matrix. Show that A can be written as a sum of two invertible matrices. HINT: for any XER, we can write A= XI + (A - XI) (b) (10 marks) Suppose V is a proper subspace of Mn.n(R). That is to say, V is a subspace, and V #Mnn(R) (there is some Me M.,n(R) such that M&V). Show that there exists an invertible matrix M e Mn.n(R) such...
2. (a) (10 marks) Suppose A is an n x n real matrix. Show that A can be written as a sum of two invertible matrices. HINT: for any l ER, we can write A = \I + (A – XI) (b) (10 marks) Suppose V is a proper subspace of Mn,n(R). That is to say, V is a subspace, and V + Mn,n(R) (there is some Me Mn,n(R) such that M&V). Show that there exists an invertible matrix M...
2. (a) (10 marks) Suppose A is an n x n real matrix. Show that A can be written as a sum of two invertible matrices. HINT: for any l ER, we can write A = \I + (A – XI) (b) (10 marks) Suppose V is a proper subspace of Mn,n(R). That is to say, V is a subspace, and V + Mn,n(R) (there is some Me Mn,n(R) such that M&V). Show that there exists an invertible matrix M...
Vetermine whether each statement is true or false. If a statement is true, give a reason or ote an appropriate statement from the text. If a statement is false provide an example that shows that the statement is not true in all cases or cite an appropriate statement from the text. (a) The determinant of the sum of two matrices equals the sum of the determinants of the matrices. o, consider the following matrica ( 8 ) and (3) O...
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(1) Answer the following questions (a) Let T : R3 → R2 be such that (i) Find a matrix A such that T(E) Az. (i) Find T(2,-3,5). (iii) Is the transformation T invertible? YES No (b) The smiley face shown at the top of the figure is transformed by various linear transformations represented by matrices A - F. Find out which matrix does which transformation. Write the letter of...
I have attached the questions and the solutions. Please do all
of questions 4 and 5
4.a) A matrix A is said to be orthogonalifA". Arv.equivalently,if AA"-A"Asl If A is anorthogonal matrix with integer entries show that every row of A has exactly one nonzero entry which is equal to ± 1. b) If A and B are invertible matrices of the same size show that adj AB adj B(adj A 5 a) Find all unit vectors parallel to the...
Let А and B be similar nxn matrices. That is, we can write A = CBC- for some invertible matrix с Then the matrices A and B have the same eigenvalues for the following reason(s). A. Both А and A. Both А and B have the same characteristic polynomial. B. Since A = CBC-1 , this implies A = CC-B = IB = B and the matrices are equal. C. Suppose that 2 is an eigenvalue for the matrix B...