
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 even function $f(x)=\cos ( \frac {π}{ω }x-φ)$, where $ω > 0$, $0 \leqslant φ < 2π$.
(1) Find the value of $φ$;
(2) If the function $f(x)$ is monotonically decreasing on $(0,3)$, find the value of $f(1)+f(2)+…+f(2017)$ when $ω$ takes the minimum value;
(3) Under the conditions of (2), if $g(x)=-2f^{2}(x- \frac {3}{2})-f(x+ \frac {3}{2})$, and for any $x_{1}$, $x_{2} \in [- \frac {3}{2π }, \frac {11}{2π }]$, $8|g(x_{1})-g(x_{2})| \leqslant \sqrt {3}m+3$ always holds, find the range of $m$.

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