Integrate `int(x^2+1)/[(x-3)(x-2)^2]dx`
Rewrite the rational function using partial fractions.
`(x^2+1)/[(x-3)(x-2)^2]=A/(x-3)+B/(x-2)+C/(x-2)^2`
`x^2+1=A(x-2)^2+B(x-3)(x-2)+C(x-3)`
`x^2+1=A(x^2-4x+4)+B(x^2-5x+6)+Cx-3C`
`x^2+1=Ax^2-4Ax+4A+Bx^2-5Bx+6B+Cx-3C`
`x^2+1=(A+B)x^2+(-4A-5B+C)x+(4A+6B-3C)`
Equate coefficients and solve for A, B, and C.
`1=A+B` (1)
`0=-4A-5B+C` (2)
`1=4A+6B-3C` (3)
Adding Equations (2) and (3) will give you
`1=B-2C`
`B=1+2C` (4)
Using equation (1) substitute variable A with `A=1-B`
into equation (3).
Using equation (4) substitute variable B with `B=1+2C`
equation (3).
...
Integrate `int(x^2+1)/[(x-3)(x-2)^2]dx`
Rewrite the rational function using partial fractions.
`(x^2+1)/[(x-3)(x-2)^2]=A/(x-3)+B/(x-2)+C/(x-2)^2`
`x^2+1=A(x-2)^2+B(x-3)(x-2)+C(x-3)`
`x^2+1=A(x^2-4x+4)+B(x^2-5x+6)+Cx-3C`
`x^2+1=Ax^2-4Ax+4A+Bx^2-5Bx+6B+Cx-3C`
`x^2+1=(A+B)x^2+(-4A-5B+C)x+(4A+6B-3C)`
Equate coefficients and solve for A, B, and C.
`1=A+B` (1)
`0=-4A-5B+C` (2)
`1=4A+6B-3C` (3)
Adding Equations (2) and (3) will give you
`1=B-2C`
`B=1+2C` (4)
Using equation (1) substitute variable A with `A=1-B`
into equation (3).
Using equation (4) substitute variable B with `B=1+2C`
equation (3).
`1=4A+6B-3C` (3)
`1=4(1-B)+6(1+2C)-3C`
`1=4-4B+6+12C-3C`
`1=10-4B+9C`
`-9=-4(1+2C)+9C`
`-9=-4-8C+9C`
`-5=C`
`B=1+2C`
`B=1+2(-5)`
`B=1-10`
`B=-9`
`A=1-B`
`A=1-(-9)`
`A=10`
`int(x^2+1)/[(x-3)(x-2)^2]dx=int10/(x-3)dx+int-9/(x-2)dx+int-5/(x-2)^2dx`
`=10ln|x-3|-9ln|x-2|+5/(x-2)+C`
The final answer is:
`=10ln|x-3|-9ln|x-2|+5/(x-2)+C `
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