Pretest Answers

Which of the following represents the inverse of the matrix? cap A is equal to the 2 by 2 matrix row 1, A b row 2, c d

Which statement is true about the determinant of a matrix?

What is the inverse of the matrix? the 2 by 2 matrix row 1, 5 7 row 2, 6 9

Which expression represents the inverse of the matrix? the 2 by 2 matrix, row 1, column 1, 1 column 2, 3 row 2, column 1, negative 1 column 2, 2

Dina encoded a secret phrase using matrix multiplication. She multiplied the clear text code for each letter by the matrix cap c is equal to the 2 by 2 matrix, row 1, column 1, negative 2 column 2, 1 row 2, column 1, 3 column 2, negative 1 to get a matrix that represents the encoded text. By which matrix does Dina multiply the encoded text to get the matrix for the clear text code?

Matrices A and B are shown. cap A is equal to the 3 by 3 matrix row 1, 1 0 1 row 2, 1 0 0 row 3, 1 1 1 cap b is equal to the 3 by 3 matrix, row 1, column 1, 0 column 2, 1 column 3, 0 row 2, column 1, x column 2, 0 column 3, y row 3, column 1, 1 column 2, negative 1 column 3, 0 What values of x and y will make the equation cap A cap b is equal to cap i true?

Given matrices S and T , which statement is true? cap s is equal to the 2 by 2 matrix, row 1, column 1, 4 column 2, 11 row 2, column 1, negative 3 column 2, negative 8 cap t is equal to the 2 by 2 matrix, row 1, column 1, negative 8 column 2, negative 11 row 2, column 1, 3 column 2, 4

Yvette encoded a secret phrase using matrix multiplication. Using cap A is equal to 1 , cap b is equal to 2 , cap c is equal to 3 , and so on, she multiplied the clear text code for each letter by the matrix cap c is equal to the 2 by 2 matrix row 1, 5 2 row 2, 2 1 to get a matrix that represents the encoded text. The matrix representing the encoded text is the 2 by 7 matrix, row 1, column 1, 48 column 2, 73 column 3, 114 column 4, 30 column 5, 136 column 6, 78 column 7, 35 row 2, column 1, 21 column 2, 32 column 3, 50 column 4, 13 column 5, 58 column 6, 35 column 7, 15 What is the secret phrase? Determine the location of spaces after you decode the text.

Calvin encoded a secret phrase using matrix multiplication. Using cap A is equal to 1 , cap b is equal to 2 , cap c is equal to 3 , and so on, he multiplied the clear text code for each letter by the matrix cap c is equal to the 2 by 2 matrix, row 1, column 1, 3 column 2, negative 2 row 2, column 1, 4 column 2, negative 3 to get a matrix that represents the encoded text. The matrix representing the encoded text is the 2 by 7 matrix, row 1, column 1, 24 column 2, 6 column 3, negative 23 column 4, 5 column 5, 21 column 6, negative 6 column 7, 35 row 2, column 1, 26 column 2, 5 column 3, negative 37 column 4, 6 column 5, 24 column 6, negative 15 column 7, 45 What is the secret phrase? Determine the location of spaces after you decode the text.

If A and B are matrices and cap A cap b is equal to cap i , which of the following represents the value of B ? cap A is equal to the 2 by 2 matrix, row 1, column 1, negative 1 column 2, 4 row 2, column 1, negative 3 column 2, 8