# Thread: Derivative of Modified Bessel Function of the Second King wrt a different order.

1. ## Derivative of Modified Bessel Function of the Second King wrt a different order.

So the derivative wrt to the same order is something I know - but a problem has come up where I'm differentiating a quotient of these functions with different orders.

K_( $\nu$+1)(z)/[tex]K_( $\nu$)(z)

Differentiating wrt to $\nu$. Should I treat the the numerator as a constant? That was my first instinct, but I think that's probably incorrect. Anyone have any suggestions?