求[1/(x+1)]-[3/(x^3+1)]当x趋近于-1时的极限

求详细过程

第1个回答  2011-04-07

思路如图:

本回答被提问者采纳
第2个回答  2011-04-07
[1/(x+1)]-[3/(x^3+1)]=[1/(x+1)]-[3/(x+1)(x^2-x+1)]=[1/(x+1)][(x^2-x+1-3)/(x^2-x+1)]=[1/(x+1)][(x-2)(x+1)/(x^2-x+1)]=(x-2)/(x^2-x+1)
将x=-1代入上式即可得极限,-1
第3个回答  2011-04-07
x^3+1=(x+1)(x^2-x+1),原式通分得:
(x^2-x+1-3)/(x^3+1)=(X^2-x-2)/(x^3+1)=(x-2)/(x^2-x+1);
极限-1。
第4个回答  2011-04-07
通分:
1/(x+1)-3/(x^3+1)=[(x^2-x+1)-2]/(x^3+1)=(x-2)/(x^2-x+1),极限是(1-2)/(1-1+1)=-1

求[1\/(x+1)]-[3\/(x^3+1)]当x趋近于-1时的极限
思路如图:

[1\/(x+1)-3\/(x^3+1)]当x无限接近-1时的极限?
首先x^3+1=(x+1)(x^2+1-x) 则通分变原式为x^2+1-x-3\/(x+1)(x^2+1-x)=(x-2)(x+1)\/(x+1)(x^2+1-x)=x-2\/x^2+1-x 所以当x趋近-1时 其极限为-3\/3=-1 采纳哦

求lim [(1\/x+1)-(3\/x^3+1)]= x→-1
简单分析一下,详情如图所示

...急~~ lim(1\/x+1-3\/X^3+1) x趋近-1 求函数极限
通分,分解因式,约去X+1 lim(x^2-x+1-3)\/(X^3+1)=lim(x^2-x-2)\/\/X^3+1)=lim(x-2)\/(x^2-x+1)=-1

...急~~ lim(1\/x+1-3\/X^3+1) x趋近-1 求函数极限
通分,分解因式,约去X+1 lim(x^2-x+1-3)\/(X^3+1)=lim(x^2-x-2)\/\/X^3+1)=lim(x-2)\/(x^2-x+1)=-1

{1\/(1-x)}-{3\/(1-x的三次方)}当x趋近于一的时候的极限是多少
1\/(1-x)-3\/(1-x^3)=(1+x+x^2-3)\/(1-x^3)=(x^2+x-2)\/(1-x^3)=(x+2)(x-1)\/(1-x)(1+x+x^2)=-(x+2)\/(1+x+x^2)所以x趋近于1时,极限=-(1+2)\/(1+1+1)=-1

lim(x→-1) [3\/(x^3+1)-1\/(x+1)]
回答:x3+1=(x+1)(x2-x+1)

当x趋近于-1时3\/(x^3+1)-1\/(x+1)的极限
😁

设lim(x→-1)[1\/(ax+1)-3\/(x^3+1)]=b
如图所示

求x趋于1时 [ 3\/(1-x^3) ]-1\/(1-x)的极限
lim(x→-1)[1\/(x+1)-3\/(x^3+1)]=lim(x→-1)[(x^2-x+1-3)\/(x^3+1)]=lim(x→-1)[(x^2-x-2)\/(x^3+1)]=lim(x→-1)[(x+1)(x-2)\/(x+1)(x^2-x+1)]=lim(x→-1)[(x-2)\/(x^2-x+1)]=-3\/3 =-1 ...

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