سیگما

`S=int (x^4-2x^2+2)/((x^2-2x+2)^2)dx`
`S=int1+(2(x-1)^2(2x-1))/((x^2-2x+2)^2)dx`
`S=x+T`
`T=int (2(x-1)^2(2x-1))/((x^2-2x+2)^2)dx`
`T=((P_1)(x))/((Q_1)(x))+int ((P_2)(x))/((Q_2)(x))dx`
`(Q_1)(x)=x^2-2x+2`
`(Q_2)(x)=x^2-2x+2`
`T=(Ax+B)/(x^2-2x+2)+int(Cx+D)/(x^2-2x+2)dx`
`A=-1 , B=3 , C=4 , D=-3`
`T=(-x+3)/(x^2-2x+2)+int(4x-3)/(x^2-2x+2)dx`
`T=(-x+3)/(x^2-2x+2)+2int(2x-2+(2-3/2))/(x^2-2x+2)dx`
`T=(-x+3)/(x^2-2x+2)+2(ln(x^2-2x+2)+1/2int(dx)/(x^2-2x+2))`
`T=(-x+3)/(x^2-2x+2)+2(ln(x^2-2x+2)+1/2int(dx)/((x-1)^2+1))`
`T=(-x+3)/(x^2-2x+2)+2ln|x^2-2x+2|+arctan(x+1)`
`S=x+(-x+3)/(x^2-2x+2)+2ln(x^2-2x+2)+arctan(x-1)`