
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
Below is the process of Xiao Hua's answer to the question. Please read it carefully and complete the corresponding tasks. Calculate: $({\sqrt{2}+1})^2}-\sqrt{4\frac{1}{2}}$. 

$\begin{array}{l}Solution: Original expression = 2+2\sqrt{2}+1-4\sqrt{\frac{1}{2}}...Step 1\\=3+2\sqrt{2}-2\sqrt{2}...Step 2\\=3...Step 3\end{array}$ 

Task 1: In the above steps, the error appears from step ____, and the reason for this error is _____. 

Task 2: Please write down the correct calculation process. 

Task 3: In addition to correcting the above error, based on your usual learning experience, give one piece of advice to other students regarding what to pay attention to when operating with square roots.

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