第2个回答 2017-10-22
lim(x+2/x-2)^x=lim[1+4/(x-2)]^x=lim[1+4/(x-2)]^(x-2)
x→∞
=lim[1+4/(x-2)]^(4*(x-2)/4)=e^4
x→∞
lim(x+2/x-2)^x=e^lim x(ln(x+2)/(x-2))=e^lim [(ln(x+2)-ln(x-2)]/(1/x)
x→∞
=e^lim [1/(x+2)-1/(x-2)]/(-1/x²) =e^lim {-4/[(x+2)(x-2)]}/(-1/x²)
x→∞
=e^lim 4x²/(x²-4)=e^4
x→∞