y=根号下x求二阶导数的
求二阶导数的
y=根号下x y=√x =x^(1/2) y′=(1/2)*x^(-1/2) y″=(1/2)*(-1/2)*x^(-3/2) =(-1/4)*[1/x^(3/2)] =(-1/4)*[1/(x*√x)] =(-1/4)*[√x/(x^2)] =-√x/(4x^2)