
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
A and B are points on the unit circle O, where point A is the intersection of the unit circle and the positive x-axis, and point B is in the second quadrant. Let ∠AOB = θ and $\sin θ = \frac{4}{5}$.
(1) Find the coordinates of point B;
(2) Calculate the value of $\frac{\sin(π+θ)+2\sin(\frac{π}{2}+θ)}{2\cos(π-θ)}$.

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