What is the integral of 1/((x+1)(x-1)^2) ?

The integral of 1/((x+1)(x-1)^2) is 1/4 ln|x+1|-1/4 ln|x-1|-1/(2(x-1))+C

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integral of 1/((x+1)(x-1)^2)

\int \frac{1}{( x + 1 ) ( x - 1 ) ^{2}} d x

\frac{1}{4} ln ∣ x + 1 ∣ - \frac{1}{4} ln ∣ x - 1 ∣ - \frac{1}{2 ( x - 1 )} + C

Solution steps

\int \frac{1}{( x + 1 ) ( x - 1 ) ^{2}} d x

Take the partial fraction of

\frac{1}{( x + 1 ) ( x - 1 ) ^{2}} : \frac{1}{4 ( x + 1 )} - \frac{1}{4 ( x - 1 )} + \frac{1}{2 ( x - 1 ) ^{2}}

= \int \frac{1}{4 ( x + 1 )} - \frac{1}{4 ( x - 1 )} + \frac{1}{2 ( x - 1 ) ^{2}} d x

Apply the Sum Rule:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= \int \frac{1}{4 ( x + 1 )} d x - \int \frac{1}{4 ( x - 1 )} d x + \int \frac{1}{2 ( x - 1 ) ^{2}} d x

\int \frac{1}{4 ( x + 1 )} d x = \frac{1}{4} ln ∣ x + 1 ∣

\int \frac{1}{4 ( x - 1 )} d x = \frac{1}{4} ln ∣ x - 1 ∣

\int \frac{1}{2 ( x - 1 ) ^{2}} d x = - \frac{1}{2 ( x - 1 )}

= \frac{1}{4} ln ∣ x + 1 ∣ - \frac{1}{4} ln ∣ x - 1 ∣ - \frac{1}{2 ( x - 1 )}

Add a constant to the solution

= \frac{1}{4} ln ∣ x + 1 ∣ - \frac{1}{4} ln ∣ x - 1 ∣ - \frac{1}{2 ( x - 1 )} + C

What is the integral of 1/((x+1)(x-1)^2) ?
The integral of 1/((x+1)(x-1)^2) is 1/4 ln|x+1|-1/4 ln|x-1|-1/(2(x-1))+C