File:Besselk0plotT400.png

Explicit plot of function BesselK0 and two its asymptotics.

$y\!=\! \mathrm{BesselK0}(x)$ is shown with thick green line.

$y\!=\! \exp(-x)\sqrt{\pi/(2x)}$ is shown with upper thin line, it approximates the function in the right hand side of the figure.

$y\!=\! \ln(2/x)-\mathrm {EulerGamma}$ is shown with lower thin line, it approcimates the function in the left hand side of the figure.