If the Bessel function of integer order n is defined as \(J_n(x)=\sum_{k=0}^{\infty} \frac{(-1)^k}{k !(n+k) !}\left(\frac{x}{2}\right)^{2 k+n}\) then \(\frac{d}{d x}\left[x^{-n} J_n(x)\right]\) is
1
\(-x^{-[n+1]} J_{n+1}(x)\)
2
\(-x^{-[n+1]} J_{n-1}(x)\)
3
\(-x^{-n} J_{n-1}(x)\)
4
\(-x^{-n} J_{n+1}(x)\)