Consider the First-Order Homogeneous System of Linear Differential Equations
$\psi(t)=\left(\begin{array}{ll}-\sin (3 t) & \cos (3 t) \\ \cos (3 t) & -\sin (3 t)\end{array}\right)$

Multiple Choice

Consider the first-order homogeneous system of linear differential equations

Which of these is the fundamental matrix (t) for this system?

A) $\psi(t) =\left(\begin{array}{ll}-\sin (3 t) & \cos (3 t) \\ \cos (3 t) & -\sin (3 t) \end{array}\right)$
B) $\Psi(t) =\left(\begin{array}{ll}\sin (3 t) & -\cos (3 t) \\ -\cos (3 t) & \sin (3 t) \end{array}\right)$
C) $\psi(t) =\left(\begin{array}{ll}\sin (3 t) & \cos (3 t) \\ \cos (3 t) & \sin (3 t) \end{array}\right)$
D) $\psi(t) =\left(\begin{array}{ll}\sin (3 t) & -\cos (3 t) \\ \cos (3 t) & \sin (3 t) \end{array}\right]$