
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 $\cos (2\theta-3\pi)= \frac {7}{25}$, and $\theta$ is an angle in the fourth quadrant,  
$(1)$ find the values of $\cos \theta$ and $\sin \theta$;  
$(2)$ find the value of $\frac {\cos ( \frac {\pi}{2}-\theta)}{\tan \theta [\cos (\pi +\theta )-1]}+ \frac {\sin (\theta- \frac {3\pi}{2})}{\tan (\pi -\theta )\cos (-\theta )}$.

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