2. Construct a 3x3 matrix A that has eigenvalues 1, 2, and 4 with the associated eigenvectors [1 1 2]T, [2 1 -2]T and [2 2 1]T, respectively.
[Hint: use P-1AP = K, where K is the diagonal matrix]
hlp me... pls guild me to the step reli no idea how to do it