
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 $f(\alpha)= \frac {\tan (2\pi-\alpha)\sin (\pi+\alpha)\sin ( \frac {3}{2}\pi-\alpha)}{\cos ( \frac {\pi}{2}+\alpha)\cos (\alpha-3\pi)}$,
(1) Simplify $f(\alpha)$;
(2) If $f(\alpha)=-2$, find the value of $\sin \alpha\cos \alpha+\cos ^{2}\alpha$.

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