2) Introduction to Matrices Flashcards

1
Q

When are two matrices equal

A

Two matrices are said to be equal if they are of the same size (i.e. they have the same real number of rows and columns) and their corresponding entries are equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a column vector

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the sum of matrices and the scalar of matrices

A
  • (A + B)ij = Aij + Bij
  • (λA)ij = λAij
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a linear combination

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is the product of 2 matrices written

A

Let A be a mxn matrix and B be a nxp matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a diagonal matrix

A

An n × n matrix is called diagonal if all the entries which are not on the diagonal are 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an identity matrix

A

The n×n identity matrix is the n×n diagonal matrix such that every diagonal entry is 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a scalar matrix

A

An n × n matrix is a scalar matrix if it is a diagonal matrix all of whose diagonal entries are equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the applications of matrices

A
  • Differential equations
  • Grayscale images
  • Representing transformations of space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the elementary row operations

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the inverse of a matrix

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the a non-interviable matrix called

A

A singular matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the proof that every invertible matrix has a unique inverse

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the proof that

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the condition for a 2x2 matrix to be invertiable

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the proof of the conditon for an invertiable matrix (Do not need to knw)

A
17
Q

What is the determinant of a 2x2 matrix

A

det(A) = ad − bc

18
Q

What is the tranpose of a matrix

A
19
Q

What are the properties of transposing a matrix

A
20
Q

Describe some of the proof of the properties of transposing a matrix

A
21
Q

Describe the proof that

A
22
Q

What is a symmetric and skew-symmetric matrix

A
  • A = AT (Symmetric)
  • AT = -A (Skew-symmetric)
  • Notice that a matrix which is symmetric or skew-symmetric must be
    square, and a skew-symmetric matrix must only have 0s on the main diagonal
    square