这个不定积分怎么算?35题
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发布时间:2024-03-05 07:18
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热心网友
时间:2024-03-05 19:45
x/(x^2-x-2)dx
x/(x-2)(x+1)
x(1/(x-2)(x+1)
=1/3xx*(1/(x-2)-1/(x+1))
=1/3(x/(x-2)-x/(x+1)dx
x/(x-2)dx
=x/(x-2)d(x-2)
=xdln(x-2)
=xln(x-2)-ln(x-2)dx
=xln(x-2)-ln(x-2)d(x-2)
=xln(x-2)-((x-2)(ln(x-2)-1)
=xln(x-2)-(x-2)ln(x-2)+x-2
=ln(x-2)(x-x+2)+x-2
=2ln(x-2)+x-2
x/(x+1)dx
=x/(x+1)d(x+1)
=xdln(x+1)
=xln(x+1)-ln(x+1)dx
=xln(x+1)-ln(x+1)d(x+1)
=xln(x+1)-[(x+1)(ln(x+1)-1)
=xln(x+1)-(x+1)ln(x+1)+x+1
=-ln(x+1)+x+1
原是=1/3[2ln(x-2)+x-2+ln(x+1)-x-1]+C
=1/3(2ln(x-2)+ln(x+1)-3]+C
=2/3ln(x-2)+1/3ln(x+1)-1+C
=2/3ln(x-2)+1/3ln(x+1)+C
热心网友
时间:2024-03-05 19:39
这个?
热心网友
时间:2024-03-05 19:40
x/(x^2-x-2)=x/[(x+1)(x-2)]
=(1/3)[1/(x+1)+2/(x-2)]
原式=(ln|x+1|+2ln|x-2|)/3+C