求极限 还请各位帮忙 50分

2025-06-23 02:41:07
推荐回答(2个)
回答1:

当x-->无穷大时,
分子分母同除民(-3)^(x+1)得
原式=lim{(x+1)/x *[(-2/3)^x*(-1/3)+(-1/3)]/[(-2/3)^(x+1)+1]}
=lim{(x/x+1/x) *[(-2/3)^x*(-1/3)+(-1/3)]/[(-2/3)^(x+1)+1]}
=lim{(1+1/x) *[(-2/3)^x*(-1/3)+(-1/3)]/[(-2/3)^(x+1)+1]}
=1*[0+(-1/3)/1]
=-1/3

回答2:

=lim | (1+1/x)[(-2/3)^x+1]/[2*(-2/3)^x-3] |
= 1*1/(-3) = -1/3