
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 $\dfrac {\sin \alpha}{\sin \alpha -\cos \alpha }=-1$  
(1) Find the value of $\tan \alpha$;  
(2) Find the value of $\dfrac {\sin ^{2}\alpha+2\sin \alpha\cos \alpha}{3\sin ^{2}\alpha +\cos ^{2}\alpha }$.

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