
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 $0 < α < \frac {π}{2}$, and $\cos (2π-α)-\sin (π-α)=- \frac { \sqrt {5}}{5}$.
(1) Find the value of $\sin α+\cos α$
(2) Find the value of $\frac {2\sin α\cos α-\sin ( \frac {π}{2}+α)+1}{1-\cot ( \frac {3π}{2}-α)}$.

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