Below you will find a mathcast for section 3.1 and finding missing values of x and y from two matrices that are equal. In order for two matrices to be equal, they must have the same dimensions and same entries.

Example A Are the following matrices equal?

external image gif.latex?%5Clarge%20$%5Cbegin%7Bpmatrix%7D%205&4&-2%5C%5C2&0&-3%5Cend%7Bpmatrix%7D=%5E%7B?%7D%20%5Cbegin%7Bpmatrix%7D%204&5&6%5C%5C-1&0&3%20%5Cend%7Bpmatrix%7D


Solution- both matrices have the same dimension, however each corresponding entry is not the same. the matrices are not equal.

external image gif.latex?%5Clarge%20$%5Cbegin%7Bpmatrix%7D%205&4&-2%5C%5C2&0&-3%5Cend%7Bpmatrix%7D%5Cneq%20%5Cbegin%7Bpmatrix%7D%204&5&6%5C%5C-1&0&3%20%5Cend%7Bpmatrix%7D

Example B Find the value of x and y. You can view the screen cast to see the solutions.




Multiplying Matrices


Example C Find the product of the matrices below:
external image gif.latex?%5Cbegin%7Bbmatrix%7D1&2&12%5C%5C12&2&1%20%5Cend%7Bbmatrix%7D%5Ccdot%5Cbegin%7Bbmatrix%7D%203&4%5C%5C4&3%5C%5C5&2%20%5Cend%7Bbmatrix%7DWatch the video below to see how we take the product of matrices.