Consider the parametric curve defined by the image of $\vec{r}(t) = \langle 2t^{2}, t^{3}-4t \rangle$.

(a) Find the velocity and speed of the parametric curve when $t = -3$.
Velocity = ,   Speed =

(b) Find an equation for the tangent line (in terms of $x$ and $y$) to the image of the parametric curve when $t = -3$.
$y =$

(c) Find $d^2y / dx^2$ when $t = -3$.

$\displaystyle \left.\frac{d^2y}{dx^2}\right|_{t=-3} =$

Using the concavity information provided by $d^2y / dx^2$, is the parametric curve above or below its tangent line when $t = -3$? Choose Below its tangent line Above its tangent line