What is the integral of 3/(3x+5) ?

The integral of 3/(3x+5) is ln|3x+5|+C

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral of 3/(3x+5)

\int \frac{3}{3 x + 5} d x

ln ∣ 3 x + 5 ∣ + C

Solution steps

\int \frac{3}{3 x + 5} d x

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= 3 \cdot \int \frac{1}{3 x + 5} d x

Apply u-substitution

= 3 \cdot \int \frac{1}{3 u} d u

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= 3 \cdot \frac{1}{3} \cdot \int \frac{1}{u} d u

Use the common integral:

\int \frac{1}{u} d u = ln (∣ u ∣)

= 3 \cdot \frac{1}{3} ln ∣ u ∣

Substitute back

u = 3 x + 5

= 3 \cdot \frac{1}{3} ln ∣ 3 x + 5 ∣

Simplify

3 \cdot \frac{1}{3} ln ∣ 3 x + 5 ∣ : ln ∣ 3 x + 5 ∣

= ln ∣ 3 x + 5 ∣

Add a constant to the solution

= ln ∣ 3 x + 5 ∣ + C