求∫dx/(x^4-1)不定积分?

如题所述

∫dx/(x^4-1)不定积分是-(1/2)arctanx + (1/4)ln|bai(x-1)/(x+1)| + C

解:

^|∫dx/(x^4-1)

=(1/2)∫[1/(x^2-1) -1/(x^2 +1) ] dx

=-(1/2)arctanx + (1/2)∫dx/(x^2-1)

=-(1/2)arctanx + (1/4)∫[ 1/(x-1) -1/(x+1) ] dx

=-(1/2)arctanx + (1/4)ln|(x-1)/(x+1)| + C

所以∫dx/(x^4-1)不定积分是-(1/2)arctanx + (1/4)ln|bai(x-1)/(x+1)| + C。

扩展资料:

1、常用几种积分公式

(1)∫0dx=c

(2)∫x^udx=(x^(u+1))/(u+1)+c

(3)∫e^xdx=e^x+c

(4)∫sinxdx=-cosx+c

(5)∫a^xdx=(a^x)/lna+c

(6)∫1/xdx=ln|x|+c

2、一般定理

定理1:设f(x)在区间[a,b]上连续,那么f(x)在[a,b]上可积。

定理2:设f(x)在区间[a,b]上单调,那么f(x)在[a,b]上可积。

定理3:设f(x)区间[a,b]上有界,且只有有限个间断点,那么f(x)在[a,b]上可积。



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第1个回答  2019-12-12

该题目中的不定积分可以将分子进行因式分解后求解。


第2个回答  2019-12-12
原式=∫dx/(x²+1)(x²-1)
=1/2[∫dx/(x²-1)-∫dx(x²+1)]
=1/4[∫dx/(x-1)-∫dx(x+1)]-tanx/2
=(1/4)ln|(x-1)/(x+1)|-(1/2)tanx+C本回答被网友采纳
第3个回答  2019-12-12
∫1/(x^4-1)dx=∫1/[(x?-1)(x?+1)]dx=(1/2)∫[1/(x?-1)]-[1/(x?+1)]dx=(1/2)∫[1/(x?-1)]dx-(1/2)∫[1/(x?+1)]dx=(1/4)∫[1/(x-1)]-[1/(x+1)]dx-(1/2)arctanx=(1/4)∫[1/(x-1)]dx-(1/4)∫[1/(x+1)]dx-(1/2)arctanx=(1/4)ln|x-1|-(1/4)ln|x+1|-(1/2)arctanx=(1/4)ln(|x-1|/|x+1|)-(1/2)arctanx
第4个回答  2019-12-12
∫dx/(x^4-1)
=(1/2)∫[1/(x^2-1) -1/(x^2 +1) ] dx
=-(1/2)arctanx + (1/2)∫dx/(x^2-1)
=-(1/2)arctanx + (1/4)∫[ 1/(x-1) -1/(x+1) ] dx
=-(1/2)arctanx + (1/4)ln|(x-1)/(x+1)| + C
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