4. (20%) It is known that the nxn tridiagonal matrix

61270fea68032.jpghas eigenvalues 6127101c4fe06.jpg
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.