Взять 2 производную x/(x^3+2)

y'=((x³+2)-x*3x²)/(x³+2)²=(x³+2-3x³)/(x³+2)²=(2-2x³)/(x³+2)²

y''=((-6x²)*(x³+2)²-(2-2x³)*2(x³+2)*3x²)/(x³+2)⁴=(-6x⁵-12x²-12x²+12x⁵)/(x₃+2)³=(6x⁵-24x²)/(x³+2)³