Given the function f (x) = 1 / (1 + x ^ 2), then f (2013) + F (2012) + F (2011) + +f(2)+f(1)+f(1/2)+…… The value of F (1 / 2011) + F (1 / 2012) + F (1 / 2013) is

Given the function f (x) = 1 / (1 + x ^ 2), then f (2013) + F (2012) + F (2011) + +f(2)+f(1)+f(1/2)+…… The value of F (1 / 2011) + F (1 / 2012) + F (1 / 2013) is

f(x)+f(1/x)=1/(1+x^2)+x^2/(1+x^2)=1
Original formula = 2012 * 1 + F (1) = 2012.5