2. Solve the initial value problems.
(a) $y'' - 5y' + 6y = 0$, $y(0) = 1$, $y'(0) = 1$
(b) $y'' - 2y' + 2y = 0$, $y(0) = -1$, $y'(0) = -1$
(c) $9y'' + 12y' + 4y = 0$, $y(0) = 1$, $y'(0) = 0$
(d) $y'' + \frac{1}{4}y = 0$, $y(\pi) = 1$, $y'(\pi) = -1$
(e) $y'' + 4y' + 4y = 0$, $y(-1) = 2$, $y'(-1) = 1$