
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
(1) Given $2\sin x=\sin ( \frac {π}{2}-x)$, find the value of $\frac {\cos 2x}{1+\sin 2x}$;
(2) Find the domain of the function $f(x)=\ln ( \sin x- \frac {1}{2})+ \sqrt {1-\tan x}$.

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