
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 $f(x) = \sin(2x + \phi)$, where $-π < \phi < 0$, and one symmetrical axis of the graph of $y = f(x)$ is the line $x = \frac{\pi}{8}$.

1. Find $\phi$;
2. Find the intervals where the function $y = f(x)$ is increasing on the interval $[0,π]$.

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