LIMX→0(x-1/x+2)^3X极限是什么
问题描述:
LIMX→0(x-1/x+2)^3X极限是什么
答
lim(x->∞) [( x-1)/(x+2)]^(3x)
=lim(x->∞) [1 +1/(x+2) ]^(3x)
let
1/y = 1/(x+2)
x= y-2
x->∞,y->∞
lim(x->∞) [1 +1/(x+2) ]^(3x)
=lim(y->∞) [1 +1/y ]^(3y-6)
=e^3
答
x趋于0吗?
那就x=0代入
=(-1/2)^0=1