• ← AngerJ
• → BesselJ

BesselI

Modified Bessel function of the first kind (Sympy, WMA)

BesselI[n, z]

returns the modified Bessel function of the first kind $I_n(z)$.

• • BesselI[0, 0]

• • BesselI[1.5, 4]

• • Plot[BesselI[0, x], {x, 0, 5}]

The special case of half-integer index is expanded using Rayleigh's formulas:

• • BesselI[3/2, x]