phân tích x2(x+1)4dx=(x+1)2(x+1)4dx−2x+1(x+1)4dx=1(x+1)2dx−2(x+1)(x+1)4dx+1(x+1)4dx
=1(x+1)2dx−2(x+1)3dx+1(x+1)4dx=d(x+1)(x+1)2−2d(x+1)(x+1)3+d(x+1)(x+1)4
toàn cái dễ rồi nhé
Cau 2 phân tích
I=1−ex1+exdx=(1−ex)exdxex(1+ex)dx đặt ex+1=t⇒exdx=dt
I=1−(t−1)(t−1)tdt=2−tt(t−1)dt=2t(t−1)dt−1t−1dt
=2(1t−1−1t)dt−d(t−1)t−1 Dễ rồi nhé