
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
In the rectangular coordinate system $xOy$, the parametric equation of line $l$ is $$\begin{cases} x=a+ \sqrt {3}t \\ y=t\end{cases}(t$$ is the parameter). Establish a polar coordinate system with the coordinate origin as the pole and the non-negative semi-axis of the $x$-axis as the polar axis. The polar equation of circle $C$ is: $\rho=4\cos\theta$. If line $l$ and circle $C$ have common points, find the range of values for the real number $a$.

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