
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
Determine the sequence number(s) of the even function(s) among the following four functions:
\[①f(x)= \sqrt[3]{x^{2}}+1\]
\[②f(x)=x+ \frac {1}{x}\]
\[③f(x)= \sqrt {1+x}- \sqrt {1-x}\]
\[④f(x)=x^{2}+x^{-2}\]

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