
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The line $\begin{cases} x=t\cos \theta, \\ y=t\sin \theta \end{cases}$ ($t$ is a parameter, $0 < \theta < \pi$) is tangent to the circle $\begin{cases} x=4+2\cos \alpha, \\ y=2\sin \alpha \end{cases}$ ($\alpha$ is a parameter). Find $\theta$.

Present the answer in LaTex format: \boxed{Your answer}
user