(1+x)^(1/x)=e只是极限状态下成立,
如果可以随便代的话lim(1+x)^(1/x) = (1+0)^(1/x)=1,显然错误.
x趋近于0正,lim[(1+x)^(1/x)/e]^(1/x)
=
x趋近于正无穷,lim[(1+1/x)^(x)/e]^x
=
lim[(1+1/x)^(xx) / e^x
=
lim e ^ (xxln(1+1/x) - x)
=
e ^ (lim(xxln(1+1/x) - x))
指数的极限用洛必达法则
(1+x)^(1/x)=e只是极限状态下成立,
如果可以随便代的话lim(1+x)^(1/x) = (1+0)^(1/x)=1,显然错误.
x趋近于0正,lim[(1+x)^(1/x)/e]^(1/x)
=
x趋近于正无穷,lim[(1+1/x)^(x)/e]^x
=
lim[(1+1/x)^(xx) / e^x
=
lim e ^ (xxln(1+1/x) - x)
=
e ^ (lim(xxln(1+1/x) - x))
指数的极限用洛必达法则