已知=ln[x+根号(x^2+1)],求二阶导数d^2y/dx^2

问题描述:

已知=ln[x+根号(x^2+1)],求二阶导数d^2y/dx^2

y'=(1+x/√(1+x^2))/(x+√(1+x^2))
=1/√(1+x^2)
y''=-x/(1+x^2)^(3/2)