
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 △ABC, sinA = $\frac{2}{3}$, and A is in the interval ($\frac{π}{2}$, π).
(1) Find the value of sin2A;
(2) If sinB = $\frac{1}{3}$, find the value of cosC.

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