Let $V$ be the space spanned by the two functions $\cos(t)$ and $\sin(t)$. Find the matrix $A$ of the linear transformation $T(f(t)) = f''(t) + 3 f'(t) + 6 f(t)$ from $V$ into itself with respect to the basis $\left\lbrace \cos(t), \sin(t) \right\rbrace$.

$A=$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$