
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 $f(x)=\sin ^{2}x+2 \sqrt {3}\sin x\cos x-\cos ^{2}x\; \;(x\in R)$.
(I) Find the smallest positive period and the monotonically decreasing interval in $[0,\pi]$;
(II) If $\alpha$ is an angle in the fourth quadrant and $\cos \alpha= \frac {3}{5}$, find the value of $f(\frac {\alpha}{2}+ \frac {7\pi}{12})$.

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