
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 that the function $y=f(x)$ is an odd function defined on $R$, when $x\leqslant 0$, $f(x)=2x+x^{2}$. If there exist positive numbers $a$ and $b$ such that when $x\in[a,b]$, the range of $f(x)$ is $[\frac{1}{b}, \frac{1}{a}]$, find the value of $a+b$.

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