Parametric Curve(s)

$$$ \forall\alpha\in\{0,2\pi\}\quad\; 5\leqslant\;k_{a}\;\leqslant40\quad\;$$$
$$$ \left \{ \begin{array}{r c l} \theta(\alpha)& = &0.2\times\sin{(k_{a}\cdot\alpha)} \\ r(\alpha)& = &0.48\times\cos{(2\cdot\alpha)} \end{array}\right .$$$