
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
Regarding the function $f(x) = 4\sin(2x + \frac{\pi}{3})$ ($x \in \mathbb{R}$), the following statements are made, among which the correct one is \_\_\_\_\_\_.
1. The expression of $y=f(x)$ can be rewritten as $y=4\cos(2x + \frac{\pi}{3})$ ($x \in \mathbb{R}$)
2. The graph of $y=f(x)$ is symmetric about the point $(-\frac{\pi}{6}, 0)$;
3. The smallest positive period of $y=f(x)$ is $2\pi$;
4. One of the axes of symmetry of the graph of $y=f(x)$ is $x=-\frac{\pi}{6}$.

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