2013
Problem - 2957
Let $f\Big(\dfrac{1}{x}\Big)=\dfrac{1}{x^2+1}$. Compute $$f\Big(\dfrac{1}{2013}\Big)+f\Big(\dfrac{1}{2012}\Big)+f\Big(\dfrac{1}{2011}\Big)+\cdots +f\Big(\dfrac{1}{2}\Big)+f(1)+f(2)+\cdots +f(2011)+f(2012)+f(2013)$$
Firstly, $$f\Big(\dfrac{1}{x}\Big)=\dfrac{1}{x^2+1} \implies f(x)= \dfrac{x^2}{x^2+1} \implies f(x) + f\Big(\dfrac{1}{x}\Big)=1$$
Therefore, we have
\begin{align*}
&f\Big(\dfrac{1}{2013}\Big)+f\Big(\dfrac{1}{2012}\Big)+f\Big(\dfrac{1}{2011}\Big)+\cdots +f\Big(\dfrac{1}{2}\Big)+f(1)+f(2)+\cdots +f(2011)+f(2012)+f(2013)\\
=&1\times 2012 + f(1)\\
=&2012 + \frac{1}{2}\\
=&\boxed{2012\frac{1}{2}}
\end{align*}