Find $d y / d x$ and $d^{2} y / d x^{2}$, and find the slope and concavity (if possible) at the given value of the parameter.
$$
\begin{array}{ll}
\underline{\text { Parametric Equations }} & \underline{\text { Point }} \\
x=\cos \theta, y=3 \sin \theta &\quad \theta=0
\end{array}
$$