
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 that $0 < α < π$ and $\tan α=-2$, find:
1. The value of $\dfrac {2\cos ( \dfrac {π}{2}+α)-\cos (π-α)}{\sin ( \dfrac {π}{2}-α)-3\sin (π+α)}$.
2. The simplification of $2\sin ^{2}α-\sin α\cos α+\cos ^{2}α$.

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