limx→无穷(x^2-5x+2/x^2+2x-3)^(2x+1)
=limx→无穷(x^2-5x+2/x^2)^(2x)
=limx→无穷(1-5/x)^(2x)
=limx→无穷(1-5/x)^[-x/5*(-10)]
=e^(-10)不对哎,答案是e^(-14),但是我不太会这个过程imx→无穷(x^2-5x+2/x^2+2x-3)^(2x+1)=imx→无穷(x^2+2x-3-7x+5/x^2+2x-3)^(2x+1)=lim[1+(-7x+5])/(x^2+2x-3)]^(2x)=lim[1+(-7x)/x^2]^(2x)=lim[1+(-7/x)]^(2x)=lim[1+(-7/x)]^[-x/7*(-14)]=e^(-14)???