
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 triangle $ABC$, where side $a$ is opposite angle $A$, side $b$ is opposite angle $B$, and side $c$ is opposite angle $C$, and it's given that $a^{2}=b^{2}+c^{2}-bc$, and $a= \dfrac{\sqrt{15}}{2}b$.
(1) Find the value of $\sin B$;
(2) Find the value of $\cos(C+ \dfrac{\pi}{12})$.

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