
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 an acute triangle $\triangle ABC$ with sides $a$, $b$, and $c$ opposite to angles $A$, $B$, and $C$ respectively, and $\sin A(a^{2}+b^{2}-c^{2})=ab\left(2\sin B-\sin C\right)$. Find:<br/>
$(1)$ the value of angle $A$;<br/>
$(2)$ the range of values for $\sin B+\sin C$.

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