integral of 2/((x+1)(x+3))

Lösung

\int \frac{2}{( x + 1 ) ( x + 3 )} d x

ln ∣ x + 1 ∣ - ln ∣ x + 3 ∣ + C

Schritte zur Lösung

\int \frac{2}{( x + 1 ) ( x + 3 )} d x

Entferne die Konstante:

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

= 2 \cdot \int \frac{1}{( x + 1 ) ( x + 3 )} d x

Ermittle den Partialbruch von

\frac{1}{( x + 1 ) ( x + 3 )} : \frac{1}{2 ( x + 1 )} - \frac{1}{2 ( x + 3 )}

= 2 \cdot \int \frac{1}{2 ( x + 1 )} - \frac{1}{2 ( x + 3 )} d x

Wende die Summenregel an:

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

= 2 (\int \frac{1}{2 ( x + 1 )} d x - \int \frac{1}{2 ( x + 3 )} d x)

\int \frac{1}{2 ( x + 1 )} d x = \frac{1}{2} ln ∣ x + 1 ∣

\int \frac{1}{2 ( x + 3 )} d x = \frac{1}{2} ln ∣ x + 3 ∣

= 2 (\frac{1}{2} ln ∣ x + 1 ∣ - \frac{1}{2} ln ∣ x + 3 ∣)

Vereinfache

2 (\frac{1}{2} ln ∣ x + 1 ∣ - \frac{1}{2} ln ∣ x + 3 ∣) : ln ∣ x + 1 ∣ - ln ∣ x + 3 ∣

= ln ∣ x + 1 ∣ - ln ∣ x + 3 ∣

Füge eine Konstante zur Lösung hinzu

= ln ∣ x + 1 ∣ - ln ∣ x + 3 ∣ + C

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

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

\int \frac{x + 3}{x ( x + 2 )} d x

\int \frac{2 \cdot 3 ^{x} - 5 \cdot 2 ^{x}}{3 ^{x}} d x

\int \frac{x ^{2}}{1 - x ^{4}} d x