1.

Evaluate: `int(3x-2)/((x+1)^2(x+3)) dx`

Answer» `Let ((3x-2))/((x+1)^(2)(x+3))=(A)/((x+1))+(B)/((x+1)^(2))+(C)/((x+3))`
`implies (3x-2)-=A(x+1)(x+3)+B(x+3)+C(x+1)^(2).`
Putting `x=-3` on both sides of (i) , we get `C=(-11)/(4).`
Putting `x=-1` on both sides of (i), we get `B=(-5)/(2).`
Comparing the coefficients of `x^(2)` on both sides of (i) ,we get
`A+C=0impliesA=-C=(11)/(4).`
`therefore ((3x-2))/((x+1)^(2)(x+3))=(11)/(4(x+1))-(5)/(2(x+1)^(2))-(11)/(4(x+3))`
`implies int((3x-2))/((x+1)^(2)(x+3))dx=(11)/(4).int (dx)/((x+1))-(5)/(2).int (1)/((x+1)^(2))dx-(11)/(4).int(dx)/((x+3))`
`=(11)/(4).log |x+1|+(5)/(2(x+1))-(11)/(4).log|x+3|+C`
`=(11)/(4)/log|(x+1)/(x+3)|+(5)/(2(x+1))+C.`


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