
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 derivative of the function

$$
u = x^{2} - \operatorname{arctg}(y + z)
$$

at the point \( A(2,1,1) \) in the direction of the point \( B(2,4,-3) \).

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