SpecFunc_BesselI1

SpecFunc_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}

Parameters:x : float
Returns:result : float