Assignment - The Matrix Day 3

What is a matrix?

A matrix is a rectangular form of data.

Matrices

• Are used by Netflix and Hulu to recommend videos for you

• Help solve higher Algebra problems such as Quadratics.

• Are used in computer graphics and video games.

A Matrix is comprised of....

• Rows

• Columns

• Elements

Size of a Matrix

The size is determined by the number of rows x number of columns. Only like size matrices can be added or subtracted from one another.

Fill in the Blanks

Identifying Elements in a Matrix

We use subscript to identify the location of an element in a matrix. It is the name of the matrix followed by row x column. Rows are top to bottom and columns are left to right.

Multiple Choice

For the matrix C given here, determine the value of the element c_34.

• $$undefined$$

• $$-10$$

• $$3$$

• $$0$$

Multiple Choice

Add the following matrices

Multiple Choice

Given the matrices A and B shown here, find A - B.

Multiple Choice

The matrix A - B is

Multiple Choice

Multiply

• 25
  25
  5
• -25
  25
  -5
• -10
  -10
  -6
• 10
  10
  6

Multiple Choice

Determinants

Determinant of 2 x 2 Matrix

det A = ad - bc

If the determinant of a matrix is not equal to zero, then the matrix has an inverse.

Fill in the Blanks

Fill in the Blanks

Multiple Choice

Find the determinant's value

• -18
• -23
• -2
• 2

Multiple Choice

Find the values of x, y and z.

• w = 13, x = 4, y = 7, z = 23
• w = 13, x = -4, y = 11, z = 23
• w = 13, x = 4, y = 11, z = 23
• w = 13, x = 4, y = 11, z = 17

Multiple Choice

What do m, n, p and q equal in this scalar matrix multiplication?

• m=8, n=9, p=-4, q=4 
• m=15, n = -45, p=20, q=-5
• m=20, n=-5, p=15, q=-45
• m=-5, n=20, p=-45, q=15

​Multiplying Matrices

Once we know we can multiply matrices, then we can start the process. First, highlight the first row in the first matrix and the first column in the second matrix. Multiply the first terms, then the second terms, and then the third terms, and so on. Add the products of each multiplication and that is the first term in the product matrix.

Multiple Choice

Find the product of the two matrices.

• 17 12

  25 18

• 17 12

  12 6

• 17 12

  7 5

• 17 12

  10 12