(a) x'=y,y'=-x

4. (20%) It is known that the nxn tridiagonal matrixhas eigenvalues for j=1,2,... ..,n. (A is called tridiagonal because all elements are zero except for those on the main diagonal and the two adjacent diagonals.) Verify Bquation (1) by calculating the eigenvalues for n = 1 and n = 2.