Hello,

I have solved a differential equation from which I get a solution that contains special functions

BesselK(a1,b1) but also BesselK(a2,b2) and many time the same function but with different parameters

Now I would like to study asymptotics of the solution for small argument of the BesselK functions.

So I would like to replace each BesselK(x,y) (for any x and y) function by the corresponding small argument asymptotics 1/Gamma(x)*(y/2)^(-x)

Is that possbile or do I have to replace each of them manually?

Thanks in advance