Chapter 14 Test

Question 1

If M = [a b c d], then M^-1 = ?

Answer 1

M^-1 = (1/ad - bc)[d (-b) (-c) a]

Question 2

Steps to solve the system using the inverse

[a b c d | e f]

Answer 2

1) Rewrite the problem
[a b c d][x y] = [e f]
2) Find the inverse of the matrix
3) Prove that the inverse times the original matrix is
[1 0 0 1]
4) Times [e f] to the inverse of the original matrix