Some new GP features zeros of Bessel functions The functions besseljzero and besselyzero return the n-th zero of the corresponding Bessel function: ? bz=besseljzero(Pi,1) %53 = 6.5531024735734022070727271054828304261 ? besselj(Pi,bz) %54 = -5.9576642536872543212799829806359075922E-40 ? bz=besselyzero(2,10) %55 = 32.143002257627550524573578252532211033 ? bessely(2,bz) %56 = -1.9968602274696716479973132188802789421E-39