True or False
(5). Suppose the matrix A and B are both invertible, then (A +...
True or False
(5). Suppose the matrix A and B are both invertible, then (A +
B)−1 = A−1 + B−1
. (6). The linear system ATAx = ATb is always consistent for any
A ∈ Rm×n, b ∈Rm .
(7). For any matrix A ∈Rm×n , it satisfies dim(Nul(A)) =
n−rank(A).
(8). The two linear systems Ax = 0 and ATAx = 0 have the same
solution set.
(9). Suppose Q ∈Rn×n is an orthogonal matrix, then the row...
. Given vectors v1, ..., vk in F n , by reducing the matrix M
with...
. Given vectors v1, ..., vk in F n , by reducing the matrix M
with v1, ..., vk as its rows to its reduced row echelon form M˜ ,
we can get a basis B of Span ({v1, ..., vk}) consisting of the
nonzero rows of M˜ . In general, the vectors in B are not in {v1,
..., vk}. In order to find a basis of Span ({v1, ..., vk}) from
inside the original spanning set {v1, ...,...
1. Let a,b,c,d be row vectors and form the matrix A whose rows
are a,b,c,d. If...
1. Let a,b,c,d be row vectors and form the matrix A whose rows
are a,b,c,d. If by a sequence of row operations applied to A we
reach a matrix whose last row is 0 (all entries are 0) then:
a. a,b,c,d are linearly dependent
b. one of a,b,c,d must be 0.
c. {a,b,c,d} is linearly independent.
d. {a,b,c,d} is a basis.
2. Suppose a, b, c, d are vectors in R4 . Then they form a...
4. Suppose that we have a linear system given in matrix form as
Ax = b,...
4. Suppose that we have a linear system given in matrix form as
Ax = b, where A is an m×n matrix, b is an m×1 column vector, and x
is an n×1 column vector. Suppose also that the n × 1 vector u is a
solution to this linear system. Answer parts a. and b. below.
a. Suppose that the n × 1 vector h is a solution to the
homogeneous linear system Ax=0.
Showthenthatthevectory=u+hisasolutiontoAx=b.
b. Now, suppose that...
Suppose ⃗v1,⃗v2,⃗v3,⃗v4 ∈ R3. Let V = {⃗v1,⃗v2,⃗v3,⃗v4} and let
X = [⃗v1|⃗v2|⃗v3|⃗v4] be the matrix...
Suppose ⃗v1,⃗v2,⃗v3,⃗v4 ∈ R3. Let V = {⃗v1,⃗v2,⃗v3,⃗v4} and let
X = [⃗v1|⃗v2|⃗v3|⃗v4] be the matrix whose columns are
⃗v1,⃗v2,⃗v3,⃗v4. Suppose further that every subset Y ⊂ V of size
two is linearly independent. Explain what form(s) rref(X), the
reduced row echelon form of X, must take in this case. Hint: you
won’t be able to pin down exact numbers for every entry of rref(X),
but you might know things like whether the entry can be zero or
not, etc.
a)Assume that you are given a matrix A = [aij ] ∈ R n×n with (1...
a)Assume that you are given a matrix A = [aij ] ∈ R n×n with (1
≤ i, j ≤ n) and having the following interesting property:
ai1 + ai2 + ..... + ain = 0 for each i = 1, 2, ...., n
Based on this information, prove that rank(A) < n.
b) Let A ∈ R m×n be a matrix of rank r. Suppose there are right
hand sides b for which Ax = b has no solution,...