
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 the following four conclusions:  
\\(① \int_{-a}^{a}(x^{2}+\sin x)dx=18\\), then \\(a=3\\);  
\\(②\\) Using the coefficient of determination \\(R^{2}\\) to describe the regression effect, the larger the value of \\(R^{2}\\), the worse the fitting effect of the model;  
\\(③\\) If \\(f(x)\\) is an odd function defined on \\(R\\) and satisfies \\(f(x+2)=-f(x)\\), then the graph of the function \\(f(x)\\) is symmetric about \\(x=1\\);  
\\(④\\) Given that the random variable \\(\xi\\) follows a normal distribution \\(N(1,\sigma^{2})\\), \\(P(\xi \leqslant 4)=0.79\\), then \\(P(\xi < -2)=0.21\\);  
Among these, the correct conclusions are numbered \_\_\_\_\_\_.

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