I am confused how the two expressions are equivalent.
The yellow expression contains a sign error; the second term should be:$$
i\left(\begin{array}{c}
-e^{-2t}\sin3t\\
+e^{-2t}\cos3t
\end{array}\right)
$$
#4
member 731016
Thank you for your replies @Orodruin and @renormalize ! Yeah that was part of my confusion is that there is a typo