I have to plot this function: Q[ω_] := ArcTan[1/ω]/(1 + 1/2*Log[(1 + ω^2)/ω^2]) And I did it through Plot[Q[ω], {ω, 0, 3}, PlotRange -> {0, 1}, PlotStyle -> {Black}] In a very simple way. The output is the following: [![enter image description here][1]][1] [1]: https://i.sstatic.net/3I5dk.jpg But here is the problem: the function, as $\omega \to 0$ must be zero. Why the plot doesn't show that behaviour? The convergence to zero is really slow (to say: for $\omega \to 10^{-309}$ I just obtained $0.0022$). Is there a way to make the plot to start from zero?