几道高数极限问题,求正确答案,最好有过程?
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发布时间:2022-05-29 10:39
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热心网友
时间:2023-10-16 00:50
解:(1)因为
lim(x—>1)(1-x)/x=(1-1)/1=0/1=0,
所以
lim(x—>1)x/(1-x)=∞;
(2) lim(x—>1)(x²-1)/(x-1)²
=lim(x—>1)(x+1)(x-1)/(x-1)²
=lim(x—>1)(x+1)/(x-1)
=∞;
(3) lim(x—>1)[1/(1-x)-3/(1-x³)]
=lim(x—>1)[(1+x+x²)/(1-x³)-3/(1-x³)]
=lim(x—>1)[(x²+x-2)/(1-x³)]
=lim(x—>1)[(x-1)(x+2)/(1-x³)]
=lim(x—>1)[(x+2)/(1+x+x²)]
=(1+2)/(1+1+1²)
=1;
((4)~(7)小题将在追问追答中解答,当身边有纸和笔等条件时再发给你手写版解答)