Class Opener:

• Solve the following system of equations using your calculator:

1.

Identifying Matrices

• A matrix is a rectangular array of numbers written with brackets. You represent a matrix with a capital letter and classify it by its dimensions. The number of horizontal rows and the number of vertical columns determine the dimensions of a matrix.

Student Check:• Write the dimensions of each matrix:

Matrix Element:

• Each number in a matrix is a matrix element. You identify a matrix element by its position within the matrix.

• You will always list the row before the column.

Matrix Element Example:

• Identify element in matrix A below:

Student Check:

• Identify each matrix element for the following matrix:

a. Find b. Find

Matrix Addition

• You preform matrix addition on matrices with equal dimensions by adding the corresponding elements, which are elements in the same position in each matrix.

Using Our Calculators

• We can use our calculators to add matrices.

• Add the following matrices:

Subtracting Matrices:

• As long as you are using your calculator you subtract matrices just like you add them.

• You must make sure that the dimensions are the same to add and subtract matrices.

Matrix Equation:

• A matrix equation is an equation in which the variable is a matrix. You can use addition and subtraction properties of equality to solve matrix equations:

Example:

• Solve for Matrix X:

Student Practice:

• Complete the following worksheet: