
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
Let vector $\mathbf{a}=\left(\begin{matrix} \frac{3}{2},\sin \theta \end{matrix}\right)$, $\mathbf{b}=\left(\begin{matrix} \cos \theta, \frac{1}{3} \end{matrix}\right)$, where $\theta \in \left(0, \frac{\pi}{2}\right)$. If $\mathbf{a} \nparallel \mathbf{b}$, then $\theta = \_\_\_\_\_\_\_\_$.

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