5. For which $a$ does the system

$$
\left\{\begin{array}{c}
x \sin a-(y-6) \cos a=0 \\
\left((x-3)^{2}+(y-3)^{2}-1\right)\left((x-3)^{2}+(y-3)^{2}-9\right)=0
\end{array}\right.
$$

have two solutions?
$$
\begin{aligned}
& a \in\left(\frac{\pi}{2}+\pi n ; \frac{3 \pi}{4}-\arcsin \frac{\sqrt{2}}{6}+\pi n\right) \cup \\
& \cup\left(\frac{3 \pi}{4}+\arcsin \frac{\sqrt{2}}{6}+\pi n ; \pi+\pi n\right), n \in Z
\end{aligned}
$$