
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 \(\alpha \in \mathbf{R}\), find the range of the function
$$
f(x)=\frac{\sin (x+\alpha)+\sin (x-\alpha)-4 \sin x}{\cos (x+\alpha)+\cos (x-\alpha)-4 \cos x}, \quad x \in\left(0, \frac{\pi}{4}\right).
$$

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