
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
The terminal side of angle α intersects the unit circle at point $(- \frac { \sqrt {5}}{5}, \frac {2 \sqrt {5}}{5})$. Find the value of cos2α:
A) $\frac {1}{5}$
B) $- \frac {1}{5}$
C) $\frac {3}{5}$
D) $- \frac {3}{5}$

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