4. Let A be an n x n matrix. Define the trace of A by the formula tr(A) = 2 . In other words, the trace of a matrix is the sum of the diagonal entries of the matrix. It is known that for two n x n matrices A and B, the trace has the property that tr(AB) = tr(BA). Each of the following holds more generally, for n x n matrices A and B, but in the interest...
Let A and B be n by n matrices and suppose that tr(AB)=0. Which of the following statements can you infer about A and B? Select one: a. At least one of the matrices A and B must equal the zero matrix O b. A must equal the zero matrix O c. B must equal the zero matrix O d. Both A and B must equal the zero matrix e. AB must equal the zero matrix O f. None of...
Show each of the 3 following matrices is symmetric and idempotent ( J is a matrix with all 1 s) For the next few problems, let X = (X1X2), ßT = (β.β;), H the lat matrix for X, and Hi the hat matrix for X i. (I 1/nJ) ii. (I H)
Let A be an m x n matrix and let B be an n x p matrix. (a) Prove that Col(AB) SColA) (b) Use part (a) to prove that the rank of AB is at most the rank of A (c) Use transpose matrices to prove that the rank of AB is also at most the rank of B.
Need help!! 1) Let A, B, C, and D be the matrices defined below. Compute the matrix expressions when they are defined; if an expression is undefined, explain why. [2 0-1] [7 -5 A= .B -5 -4 1 C- ,D= (-5 3] [I -3 a) AB b) CD c) DB d) 3C-D e) A+ 2B 2) Let A and B be the matrices defined below. 4 -2 3) A=-3 0, B= 3 5 a) Compute AB using the definition of...
I will rate if correct 4. (10 pts) Let A,B be square matrices with the same size n × n, and let c be a constant. True or False: (a) (AB)-1- B-1A-1 (b) ABメBA in general. (c) det(AB) = det(B) * det(A) (d) (CAB)1A (e) rank(A+ B) S rank(A) + rank(B)
44. a.Let A and B be two 2 × 2 matrices,Let Tr denote the trace and det denote the determinant. Prove that Tr(AB)-Tr(BA) and det(AB) - det(BA). b. If A is any matrix in SLa(R), prove that det ((-A-t +1 where t = Tr(A). 44. a.Let A and B be two 2 × 2 matrices,Let Tr denote the trace and det denote the determinant. Prove that Tr(AB)-Tr(BA) and det(AB) - det(BA). b. If A is any matrix in SLa(R), prove...
I will give a rate! please show work clearly! thanks! 12. Let A = CD , where C is an invertible n × n matrix and A and D are n × n matrices. Prove that the matrix DC is similar to A. 12. Let A = CD , where C is an invertible n × n matrix and A and D are n × n matrices. Prove that the matrix DC is similar to A.
Let Y = (Yİ Y2 Yn)' be a random vector taking on values in Rn with mean μ E Rn and covariance matrix 2. Also let 1 be the ones vector defined by 1-(1 1) 5.i Find the projection matrix Hy where V is the subspace generated by 1 5.ii Show that Hy is symmetric and idempotent. 5.iii Let x = (a a . .. a)', where a E Rn. Show that Hvx = x. 5.iv Find the projection of...
3. (10%) Let C = AB, where A and B are both n by n matrices. The element located at row i and column of C is represented by C, and computed as C, = A, B, + A,B2, + ... + 4,B, a) Express C, using the X (summation) notation. b) Evaluate c, if Ak = 2 and B, = 3 for all k, k = 1,2,...n.