Corrected Errata:
 Practice exam 2, 2b, a constant C_{1} was missing in the solution. (Thanks to Peter Kim)
 Practice exam 1, 14, a sign was wrong for the eigenvalue n^{4}+n^{2}+1 of the operator T.
(Thanks to Lisa Rotenstein and Charles Liu)
 Practice exam 4, 13, the final solution had a factor 16 missing. There was also a sign error
for the coefficients c_{n}^{2} = 116 n^{2} and a sin(n t) should have been
sin(n x). (Thanks to Heidi Liu and Allen Yang)
 Practice exam 3, 13, there was ghost factor 8 in the solution which should not have been there.
(Thanks to Trung Nguyen.)
 Practice exam 3, 11, in the intermediate step of the integration by parts,
factors n were missing. The result is correct. (Thanks to Peter Kim)
 Practice exam 3, TF 18, the solution labeled it false, but it is true. The explanation was
correct. (Thanks to Taylor Yi).
I,li>Practice exam2, 13a), when rewriting the series with the b_{n}, there had been a typo
(4 instead of 8). (Thanks to Megan Blewett).
