BesselI1¶

BesselI1(x)¶

Modified first kind Bessel function of order 1.

$\forall x \in \Rset, \quad \mathrm{I}_1(x) = \sum_{m=0}^\infty\frac{1}{m!(m+1)!}\left(\frac{x}{2}\right)^{2m+1}$