Answer
(a) $e^{x}$ is a solution.
(b) $e^{-x}$ is a solution.
(c) $\cos{x}$ is a solution.
(d) $\sin{x}$ is a solution
Work Step by Step
(a) $e^{x}$ is a solution.
(b) $e^{-x}$ is a solution.
(c) $\cos{x}$ is a solution.
(d) $\sin{x}$ is a solution.