(1)原式=lim(x→0)[(e^x-1-x)/x(e^x-1)]=lim(x→0)[x²/2+ο(x²)]/x²=1/2(2)原式=lim(x→0+)(1/x)^x=lim(x→0+)1/x^x=1(3)原式=lim(x→0)[x³/6-x³/3+ο(x³)]/(x³/3)=lim(x→0)[-x³/6+ο(x³)]/(x³/3)=-1/2