BesselJ function
BESSELJ(x,n) returns the Bessel function of the first kind of order n evaluated at x. x can be any real number. n is the order of the Bessel function; if it is not an integer, it is truncated.
The Bessel function of the first kind is defined by the integral:
$$ J_n(x) = \frac{1}{\pi}\int_0^\pi \cos(n\theta - x\sin\theta)\,d\theta $$
Examples
BESSELJ(0,0) equals 1
BESSELJ(1,0) equals 0.7651977
BESSELJ(1,1) equals 0.4400506
Calculator
Graph
Graph for different order parameters n
