1. 2.3 Modeling Real World Data with Matrices

2. Matrix – a rectangular array or terms called elements.
Elements are arranged in rows and columns and enclosed by brackets.
A matrix with m rows and n columns is an m x n matrix.
The dimensions of the matrix and m and n.
Named using a capital letter.

3. Two matrices are equal if and only if they have the same dimensions and are identical, element by element.
Ex 2

4. Addition – can add if same size
Ex 3

5. Additive Identity – for every matrix A, another matrix can be found so that their sum is A.

6. Ex 4
Fins S – T.

7. Scalar multiplication – multiply each element of the matrix by the scalar.
Ex 5Find 4A if A=

8. Matrix multiplication – the product of an m x n matrix and an n x r matrix is an m x r matrix.
Ex 6
Find AB
Find BC

9. Ex 7