Operations with Matrices: Multiplication TSWBAT perform scalar multiplication; multiply to matrices

Scalar Multiplication Multiplying a matrix by a real number Multiply each element by the real number Just like distributing -1 4 3 7 0 -8 5 -5 20 15 35 -40

Examples 3 -4 1 6 -4 5 7 4 5 -1 3 -2 8 -2 4 7 -3 5 2 + 0 -2 6 4

Class work WB pg 23 1-6 Turn in when finished Homework Worksheet

Multiplying Two Matrices You can only multiply matrices if the columns of the first matrix have the same number of elements as the rows of the second matrix -1 2 4 0 7 -5 3 1 6 8 2 x 2 2 x 3 2 x 3

Multiplying Two Matrices Multiply the elements of each row of the first matrix by the corresponding elements in each column of the second matrix Find the sum of each set of products -1 2 4 0 7 -5 3 1 6 8 -1(7) + 2(1) The answer goes in the corresponding spot, Row 1 Column 1

Example -1 2 4 0 7 -5 3 1 6 8 -1(7) + 2(1) -1(-5) + 2(6) -1(3) + 2(8) -1 2 4 0 7 -5 3 1 6 8 -1(7) + 2(1) -1(-5) + 2(6) -1(3) + 2(8) 4(7) + 0(1) 4(-5) + 0(6) 4(3) + 0(8) -5 17 13 28 -20 12 -7 + 2 5 + 12 -3 + 16 28 + 0 -20 + 0 12 + 0

Examples 3 -2 1 0 0 -5 6 8 0 -2 5 1 -3 6 4 3 1 7 1 2 -3 5 8 6 4 -2 -8

Using your Calculator Push the green ALPHA button Push the zoom button Choose the dimensions of the matrix, click OK Enter the numbers Choose the operations and repeat to enter the second matrix If it says error, the 2 matrices cannot be multiplied

Class work WB page 24 14-18 Homework Worksheet