求下列不定积分1 x²-2x+5-搜答案-神马作文网

详见：http://hi.baidu.com/xxllxhdj/blog/item/0f5c8a0c96aab9c762d986c5.html

∫1/(x^2+2x+5)dx=∫1/[(x+1)^2+4]dx=∫(1/4)/[[(x+1)/2]^2+1]dx=∫(1/4)·2/[[(x+1)/2]^2+1]d((x+1)/2)=(1/2)∫1

∫(x^2-1)sin2xdx先括号拆开=∫x^2*sin2xdx-∫sin2xdx=-1/2*∫x^2dcos2x-1/2*∫sin2xd2x先凑微分=-1/2*∫x^2dcos2x-1/2*∫si

令(1+2x)/[x(x+1)]=A/x+B/(x+1)令x=0,A=(1+0)/(0+1)=1令x=-1,B=(1-2)/(-1)=1∴(1+2x)/[x(x+1)]=1/x+1/(x+1)∫(1+

原式=∫(x+1)/x²+∫xlnxdx=∫x/x²+∫1/x²+1/2∫lnxdx²=∫1/x+∫1/x²+1/2*x²lnx-1/2∫x

∫ln(1+x)/(1+x)dx=∫ln(1+x)/(1+x)d(1+x)=∫ln(1+x)dln(1+x)=[ln(1+x)]²/2+C

1/(x+1)(x+2)(x+3)=1/(x+1)[1/(x+2)-1/(x+3)]=1/[(x+1)(x+2)]-1/[(x+1)(x+3)]=1/(x+1)-1/(x+2)-1/2[1/(x+1)

很简单啊,好好观察形状就好解了

先用分部积分法,然后用t=1-5x^2简化,结果记得换回x　　我算的结果1/4(1-5x^2)^10*x^4-1/1200x^6+1/1100x^(11/2)　　希望对你有用

有理分式积分法,将分式分为几个部分分式

分部积分法∫xe^x/(1+x)^2dx＝－∫xe^xd[1/(1+x)]＝－xe^x/(1+x)＋∫(1+x)e^x×1/(1+x)dx＝－xe^x/(1+x)＋∫e^xdx＝－xe^x/(1+x)

∫(1/x^2+6x+5)dx=∫(1/[(x+5)(x+1)]dx=1/4∫(1/(x+1)-1/(x+5)dx=1/4[ln(x+1)-ln(x+5)]+C非要用什么换元法的话,令x+1=t,dx

凑微分法∫(e^2x-cosx/3)dx=∫e^2xdx-∫cosx/3dx=1/2∫e^2xd(2x)-3∫cosx/3d(x/3)=1/2e^2x-3sinx/3+c

∫1/[sin(2x)+2sinx]dx=∫1/[2sinxcosx+2sinx]dx=∫1/(2sinx*[cosx+1])dx=∫1/(sinx*[2cos^2(x/2)])d(x/2)=1/2∫

设(2x²-3x-3)/[(x-1)(x²-2x+5)]=[a/(x-1)]+[(bx+c)/(x²-2x+5)]则2x²-3x-3=a(x²-2x+