
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
Given the function $f(x)=2\sqrt{3}\cos^2\left(\frac{\pi}{2}+x\right)-2\sin(\pi+x)\cos x-\sqrt{3}$.  
$(1)$ Find the extreme values of $f(x)$ on the interval $\left[\frac{\pi}{4}, \frac{\pi}{2}\right]$.  
$(2)$ If $f(x_0-\frac{\pi}{6})=\frac{10}{13}$, where $x_0\in\left[\frac{3\pi}{4}, \pi\right]$, find the value of $\sin 2x_0$.

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