BesselK¶

BesselK(nu, x)¶

Modified second kind Bessel function of order $\nu$ .

$\forall x \in \Rset, \quad \mathrm{K}_{\nu}(x) = \frac{\pi}{2}\frac{\mathrm{I}_{-\nu}(x)-\mathrm{I}_{\nu}(x)}{\sin{\nu\pi}}$