(x³/(x-1)²)'=[3x²(x-1)²-2x³(x-1)]/(x-1)⁴=[3x²(x-1)-2x³]/(x-1)³=(x³-3x²)/(x-1)³
y'=3x^2(x-1)^2-x^3(2x-2)/(x-1)^4 =x^4-4x^3+3x^2/(x-1)^4算到这样可以吗？
