Consider the Following Nonlinear System:

Which of the Following $\left(\frac{\pi}{6}, \frac{5 \pi}{18}\right)$

Multiple Choice

Consider the following nonlinear system:

Which of the following statements are true? Select all that apply.

A) $\left(\frac{\pi}{6}, \frac{5 \pi}{18}\right)$ is an unstable saddle point.
B) $\left(-\frac{\pi}{6}, \frac{\pi}{18}\right)$ is a stable center.
C) $\left(-\frac{\pi}{6}, \frac{\pi}{36}\right)$ is a stable center.
D) $\left(\frac{\pi}{3},-\frac{5 \pi}{18}\right)$ is an asymptotically stable spiral point.
E) $\left(\frac{3 \pi}{6},-\frac{\pi}{18}\right)$ is an improper node.
F) $\left(\frac{\pi}{3}, \frac{\pi}{36}\right)$ is a stable center.