
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 vectors $\overrightarrow {a}$=(sinx, $\frac {3}{2}$) and $\overrightarrow {b}$=(cosx, -1),
(I) Find the value of tan2x when $\overrightarrow {a}$ is parallel to $\overrightarrow {b}$;
(II) Find the range of the function f(x)=($\overrightarrow {a}$+$\overrightarrow {b}$)•$\overrightarrow {b}$ on the interval [0, $\frac {π}{2}$].

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