, then n lim Let Ά be a square matrix. Prove that if ρ(A)<1 Use the...
IDY in < oo and lim - Yn < 0o. Prove that lim,+ 1. Let In > 0. Yn > 0 such that lim,- Yn) < lim,-- In lim,+ Yn: i tn < oo and lim yn < . Prove that lim. In 1. Let In 20, yn 0 such that lim Yn) < limn+In lim + Yr
Let A be an mx n matrix and B be an n xp matrix. (a) Prove that rank(AB) S rank(A). (b) Prove that rank(AB) < rank(B).
Let ne Nj. Prove that n < 2(6(n)).
Let U ? Rmxn. Prove that if UTI-In, then n < m.
(6) Let A denote an m x n matrix. Prove that rank A < 1 if and only if A = BC. Where B is an m x 1 matrix and C is a 1 xn matrix. Solution (7) Do the following: (a) Use proof by induction to find a formula for for all positive integers n and for alld E R. Solution ... 2 for all positive (b) Find a closed formula for each entry of A" where A...
c) Let Ae R"n be nonsingular and let -be any natural matrix norm on R be an eigenvalue of A. Prove that 1/| A-1|| S AS 11A|l. Let A
Exercise 15: Let (cn) be a sequence of positive numbers. Prove: lim infºn+1 < lim infch/n. n700 Cnn +00 What is the corresponding inequality for the lim sup?
(a) Let S be a symmetric positive definite matrix and define a function | on R" by 1/2 xx Sx . Prove that this function defines a vector norm. Hint: Use the Cholesky decomposition. (b) Find an example of square matrices A an This shows that ρ(A) is not a norm. Note: there are very simple examples. d B such that ρ(A+B)>ρ(A) + ρ(8) (a) Let S be a symmetric positive definite matrix and define a function | on R"...
Let A be an m x n matrix of unspecified rank. Let b e Rm, and let Prove that this infimum is attained. In other words, prove the existence of an ax for which l|Ax bll p. In this problem, the norm is an arbitrary one defined on Rm. Let A be an m x n matrix of unspecified rank. Let b e Rm, and let Prove that this infimum is attained. In other words, prove the existence of an...
for every n. Prove: If (a) converges, then 11. Let (a.) and (b) be sequences such that a, b, < so does (bn). There are several ways to prove this; at least one doesn't involve Cauchy sequences or e. Be careful though you don't know that () converges so make sure that your method of proof doesn't in fact require (b) to converge.