radians. 4. Below is a 33 matrix where the third column is missing. a. [1/3 1/2 A = 1/3 0 1/3 -1/2 Calculate the elements of the third column so that the matrix below is orthogonal. It must be a unit vector that is orthogonal to the other two columns. There are two possible solutions. You can pick one. b. Find its determinant. C. Find its rank. d. Find its trace. e. Find its characteristic equation and solve the eigenvalues f. Find its inverse matrix.