(1) Verify by direct multiplication that the given matrices are inverses of one another.
(2) Let A =
Find the third column vector of A^(-1) without determining the other columns of the inverse matrix. (use the set up from the video before the Gauss-Jordan algorithm was introduced).
(3) Determine A^(-1), if possible, using the algorithm introduced in the video lesson. If A^(-1) exists, check your answer by verifying that AA^(-1) = I_n.
(a) A =
(b) A =
(4) Use A^(-1) to find the solution to the given system.
(5) Determine if the given statement is true or false. Justify (if false, use a counter example).
(a) Every square matrix that does not contain a row of zeros is invertible.
(b) If A and B are invertible matrices, then so is AB.
(c) If A is an invertible matrix such that A^2 = A, then A is the identity matrix.