Captured On
[2020-02-05 Wed 21:13]
Source
.Session 9: Matrix Multiplication | Part B: Matrices and Systems of Equations | 1. Vectors and Matrices | Multivariable Calculus | Mathematics | MIT OpenCourseWare

1 Chalkboard

Figure 1: What is a matrix?

Figure 1: What is a matrix?

Figure 2: Change coordinate systems

Figure 2: Change coordinate systems

Figure 3: Entries in matrix multiplication

Figure 3: Entries in matrix multiplication

Figure 4: Nmemotecnic rule for matrix multiplication

Figure 4: Nmemotecnic rule for matrix multiplication

2 How we can set up 2 matrix for its multiplication?

2.1 Front

How we can set up 2 matrix for its multiplication?

I asking for the mnemonic rule of AB multiplication

2.2 Back

3 What kind of vector we form as a matrix?

3.1 Front

What kind of vector we form as a matrix?

3.2 Back

  • row-vector as \(1 \times n\) matrix
  • column-vector as \(m \times 1\) matrix

4 Matrix operations - Scalar multiplication

4.1 Front

Matrix operations - Scalar multiplication

\(cA\)

4.2 Back

\(cA = (ca_{ij})\)

  • Multiply each entry

5 Matrix addition

5.1 Front

Matrix addition

A + B

5.2 Back

  • The two matrix must have the same number of rows and the same number of columns
  • Sum each entry of first matrix with the same entry of the other matrix

6 Matrix operation - Transposition

6.1 Front

Matrix operation - Transposition

6.2 Back

  • Notation: \(A^T\), \(A’\)
  • Making the rows of \(A\) the columns of the new matrix
  • \(n \times m\) matrix \(\to\) \(m \times n\) matrix
  • \(A^T = (a_{ji})\)