∫x2+x+x+1(x+2)(x+1)⇒x2+x+1(x+2)(x+1)2=A(x+2)+B(x+1)+C(x+1)=
x2+x+1=(x2+2x+1)A+B(x2+3x+12)+c(x+2)
1=A+B+ 1=3A+4B
1=2A+3B+C)2 (1=A+B)3
1=A+2B+2C 3=3A+3B
2=4A+2B+2C ______________
_____________ −2=B
1=3A+4B 1=3A−8⇒3A=9
A=3
−3+(−4)+2C=1
∫x2+x+x+1(x+2)(x+1)2=∫3(x+2)+∫−2x+1+∫1(x+1)2
=3 ln(x+2)−2ln(x+1)−9x+1)+C