What is the integral of 1/(x^2+10x+9) ?

The integral of 1/(x^2+10x+9) is 1/8 ln|x+1|-1/8 ln|x+9|+C

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integral of 1/(x^2+10x+9)

\int \frac{1}{x ^{2} + 10 x + 9} d x

\frac{1}{8} ln ∣ x + 1 ∣ - \frac{1}{8} ln ∣ x + 9 ∣ + C

Solution steps

\int \frac{1}{x ^{2} + 10 x + 9} d x

Take the partial fraction of

\frac{1}{x ^{2} + 10 x + 9} : \frac{1}{8 ( x + 1 )} - \frac{1}{8 ( x + 9 )}

= \int \frac{1}{8 ( x + 1 )} - \frac{1}{8 ( x + 9 )} 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}{8 ( x + 1 )} d x - \int \frac{1}{8 ( x + 9 )} d x

\int \frac{1}{8 ( x + 1 )} d x = \frac{1}{8} ln ∣ x + 1 ∣

\int \frac{1}{8 ( x + 9 )} d x = \frac{1}{8} ln ∣ x + 9 ∣

= \frac{1}{8} ln ∣ x + 1 ∣ - \frac{1}{8} ln ∣ x + 9 ∣

Add a constant to the solution

= \frac{1}{8} ln ∣ x + 1 ∣ - \frac{1}{8} ln ∣ x + 9 ∣ + C

What is the integral of 1/(x^2+10x+9) ?
The integral of 1/(x^2+10x+9) is 1/8 ln|x+1|-1/8 ln|x+9|+C