What is the integral of (2r+1)/(r^2-3r+2) ?

The integral of (2r+1)/(r^2-3r+2) is -3ln|r-1|+5ln|r-2|+C

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral of (2r+1)/(r^2-3r+2)

\int \frac{2 r + 1}{r ^{2} - 3 r + 2} d r

- 3 ln ∣ r - 1 ∣ + 5 ln ∣ r - 2 ∣ + C

Solution steps

\int \frac{2 r + 1}{r ^{2} - 3 r + 2} d r

Take the partial fraction of

\frac{2 r + 1}{r ^{2} - 3 r + 2} : - \frac{3}{r - 1} + \frac{5}{r - 2}

= \int - \frac{3}{r - 1} + \frac{5}{r - 2} d r

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{3}{r - 1} d r + \int \frac{5}{r - 2} d r

\int \frac{3}{r - 1} d r = 3 ln ∣ r - 1 ∣

\int \frac{5}{r - 2} d r = 5 ln ∣ r - 2 ∣

= - 3 ln ∣ r - 1 ∣ + 5 ln ∣ r - 2 ∣

Add a constant to the solution

= - 3 ln ∣ r - 1 ∣ + 5 ln ∣ r - 2 ∣ + C

What is the integral of (2r+1)/(r^2-3r+2) ?
The integral of (2r+1)/(r^2-3r+2) is -3ln|r-1|+5ln|r-2|+C