
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
Find the value of the following expressions:

(1) cos $\frac{25}{3}\pi$ + tan(-$\frac{15}{4}\pi$);

(2) 2($\overrightarrow{a}$ - $\overrightarrow{b}$) - (2$\overrightarrow{a}$ + $\overrightarrow{b}$) + 3$\overrightarrow{b}$

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