What is the integral of (6x+11)/(x^2+2x+5) ?

The integral of (6x+11)/(x^2+2x+5) is 3ln|x^2+2x+5|+5/2 arctan(1/2 (x+1))+C

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integral of (6x+11)/(x^2+2x+5)

\int \frac{6 x + 11}{x ^{2} + 2 x + 5} d x

3 ln x^{2} + 2 x + 5 + \frac{5}{2} arctan (\frac{1}{2} (x + 1)) + C

Solution steps

\int \frac{6 x + 11}{x ^{2} + 2 x + 5} d x

Complete the square

x^{2} + 2 x + 5 : (x + 1)^{2} + 4

= \int \frac{6 x + 11}{( x + 1 ) ^{2} + 4} d x

Apply u-substitution

= \int \frac{6 u + 5}{u ^{2} + 4} d u

Expand

\frac{6 u + 5}{u ^{2} + 4} : \frac{6 u}{u ^{2} + 4} + \frac{5}{u ^{2} + 4}

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{6 u}{u ^{2} + 4} d u + \int \frac{5}{u ^{2} + 4} d u

\int \frac{6 u}{u ^{2} + 4} d u = 3 ln u^{2} + 4

\int \frac{5}{u ^{2} + 4} d u = \frac{5}{2} arctan (\frac{u}{2})

= 3 ln u^{2} + 4 + \frac{5}{2} arctan (\frac{u}{2})

Substitute back

u = x + 1

= 3 ln (x + 1)^{2} + 4 + \frac{5}{2} arctan (\frac{x + 1}{2})

Simplify

3 ln (x + 1)^{2} + 4 + \frac{5}{2} arctan (\frac{x + 1}{2}) : 3 ln x^{2} + 2 x + 5 + \frac{5}{2} arctan (\frac{1}{2} (x + 1))

= 3 ln x^{2} + 2 x + 5 + \frac{5}{2} arctan (\frac{1}{2} (x + 1))

Add a constant to the solution

= 3 ln x^{2} + 2 x + 5 + \frac{5}{2} arctan (\frac{1}{2} (x + 1)) + C

What is the integral of (6x+11)/(x^2+2x+5) ?
The integral of (6x+11)/(x^2+2x+5) is 3ln|x^2+2x+5|+5/2 arctan(1/2 (x+1))+C