Parametric Curve(s)

$$$ \forall\alpha\in\{0,2\pi\}\quad\; 2\leqslant\;k_{a}\;\leqslant3.2\quad\;$$$
$$$ \left \{ \begin{array}{r c l} \theta(\alpha)& = &\cos{(k_{a}\cdot\alpha)} \\ r(\alpha)& = &0.24\times\sin{\alpha} \end{array}\right .$$$