[LA] Matrix Multiplication and Inverse Matrix

Contents

1. Matrix Multiplication (4 ways!)

2. Inverse Matrix

 

1. Matrix Multiplication

 

---

 

 

 

1) inner product (regular)

2) (important) column operation 

3) (important) row operation 

4) external product

 

 

 

2. Inverse Matrix

 

---

 

1) definition

 

2) singular case

reason for A is not invertible 

행렬안의 두 벡터(row or column)가 dependent하다면 linear combination(선형조합)으로 모든 벡터를 만들 수는 없습니다.

3) non-singular case 

reason for A is invertible

행렬안의 두 벡터(row or column)가 independent 하다면 선형조합으로 모든 벡터를 만들 수 있습니다.