
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 $f(\theta)= \frac {\sin (\theta-5\pi)\cos (- \frac {\pi}{2}-\theta)\cos (8\pi-\theta)}{\sin (\theta- \frac {3\pi}{2})\sin (-\theta-4\pi)}$  
Find:  
(1) $f(\theta)$;  
(2) $f( \frac {4}{3}\pi)$

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