Homepage › Solution manuals › Gilbert Strang › Linear Algebra and Learning from Data › Exercise 4.2.5
We have F4 = [1 1 1 1 1 i −1 −i 1−1 1 −1 1−i−1 i ]
The eigenvalues of C are F4c = [1 0 0 0 ]
The three roots for 1 + z + z2 + z3 = 0 are z = e2πki∕4, for k = 1,2,3