(x+3)³=x³+9x²+27x+27(x+3)²=x²+6x+9x³=(x+3)³-9(x²+3x+3)=(x+3)³-9(x²+6x+9-3x-9+3)=(x+3)³-9(x+3)²+27(x+3)-27x³/(x+3)=(x+3)²-9(x+3)+27-27/(x+3)=x²-3x+9-27/(x+3)原式=x³/3-3x²/2+9x-27ln|x+3|+C
x³
