How do you integrate int (x+3)/(x^2(x-1) ) using partial fractions?

1 Answer
Apr 15, 2018

4ln|(x-1)/x|+3/x+C, or, ln(1-1/x)^4+3/x+C.

Explanation:

Here is a way to find the Integral I=int(x+3)/{x^2(x-1)}dx,

without using partial fractions.

I=int(x+3)/{x^2(x-1)}dx,

=int{x/{x^2(x-1)}+3/{x^2(x-1)}}dx,

=int[1/{x(x-1)}+3*(x-(x-1)}/{x^2(x-1)}]dx,

=int[1/{x(x-1)}+3{x/{x^2(x-1)}-(x-1)/{x^2(x-1)}}]dx,

=int[1/{x(x-1)}+3/{x(x-1)}-3/x^2]dx,

=int4/{x(x-1)}dx-3int1/x^2dx,

=4int{x-(x-1)}/{x(x-1)}dx--3*x^(-2+1)/(-2+1),

=4int{1/(x-1)-1/x}dx+3/x,

=4{ln|(x-1)|-ln|x|}+3/x.

rArr I=4ln|(x-1)/x|+3/x+C, or, ln(1-1/x)^4+3/x+C.

Enjoy Maths.!