BesselK function
BESSELK(x,n) returns the modified Bessel function of the second kind (also called the Basset function) of order n evaluated at x. x must be greater than 0. n is the order of the Bessel function; if it is not an integer, it is truncated.
The modified Bessel function of the second kind is defined as:
$$ K_n(x) = \frac{\pi}{2} \cdot \frac{I_{-n}(x) - I_n(x)}{\sin(n\pi)} $$
Unlike BESSELY, the function BESSELK is always positive and decays exponentially as x increases.
Examples
BESSELK(1,0) equals 0.4210244
BESSELK(1,1) equals 0.6019072
Calculator
Graph
Graph for different order parameters n
