Scalar and Matrix Multiplication

Question 1

Which of the following statements are true about inverse matrices?

Revolt · Accepted Answer

B: If A and B are inverse matrices, then A and B must be square matrices.; C: The determinant of a singular matrix is equal to zero.; E: If A and B are inverse matrices, then .; F: Any zero matrix does not have an inverse.; G: If B = A–1, then A = B–1.

Question 2

a = b = c = d =

Revolt · Accepted Answer

Part 2: -3; Part 3: -1; Part 4: 1

Question 3

c11 = c12 = c21 = c22 = So the matrices inverses of one another.

Revolt · Accepted Answer

Part 1: 1; Part 2: 0; Part 3: 0; Part 4: 1

Question 4

Question 4

Revolt · Accepted Answer

B

Question 5

Find the elements of D.a =

Revolt · Accepted Answer

-9

Question 6

Select the matrix that is the inverse of:

Revolt · Accepted Answer

C:

Question 7

Use your knowledge of inverses and matrix multiplication to answer the following:AB =

Revolt · Accepted Answer

C: I

Question 8

Internet sites often ask for a secret phrase to recover lost passwords. Jason encoded a secret phrase using matrix multiplication. He multiplied the clear text code for each letter by the matrix: The matrix representing the encoded text is:Jason’s secret phrase is:

Revolt · Accepted Answer

B: CATS RULE DOGS DROOL

Question 9

Explain why it is important to be able to perform matrix operations by hand when a calculator can do them for you.

Revolt · Accepted Answer

It is important to be able to perform matrix operations by hand because calculators may not always be available, such as on certain tests or if the calculator dies. Finding an inverse or doing other operations by hand also helps you understand the process instead of just getting an answer. Calculators may show decimal approximations rather than exact fractions. For small or simple matrices, working by hand can sometimes be faster. Finally, a matrix could contain a variable, which many calculators cannot handle easily.

Question 10

Question 10

Revolt · Accepted Answer

-1

Scalar and Matrix Multiplication Answers

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