usepackage{pgfplots}
usepackage{pst-math}

begin{tikzpicture}
begin{axis}[
    domain=-10:10,
    xscale=1.5,yscale=1,
    xmin=-3, xmax=3,
    ymin=-100, ymax= 100,
    samples=1000,
    axis lines=center,
]
    addplot+[mark=none] {atan(x) - x/(1+x^2)};
end{axis}
end{tikzpicture}