Integralen av $$$- \frac{1}{t}$$$

Bestäm $$$\int \left(- \frac{1}{t}\right)\, dt$$$.

Tillämpa konstantfaktorregeln $$$\int c f{\left(t \right)}\, dt = c \int f{\left(t \right)}\, dt$$$ med $$$c=-1$$$ och $$$f{\left(t \right)} = \frac{1}{t}$$$:

$${\color{red}{\int{\left(- \frac{1}{t}\right)d t}}} = {\color{red}{\left(- \int{\frac{1}{t} d t}\right)}}$$

Integralen av $$$\frac{1}{t}$$$ är $$$\int{\frac{1}{t} d t} = \ln{\left(\left|{t}\right| \right)}$$$:

$$- {\color{red}{\int{\frac{1}{t} d t}}} = - {\color{red}{\ln{\left(\left|{t}\right| \right)}}}$$

Alltså,

$$\int{\left(- \frac{1}{t}\right)d t} = - \ln{\left(\left|{t}\right| \right)}$$

Lägg till integrationskonstanten:

$$\int{\left(- \frac{1}{t}\right)d t} = - \ln{\left(\left|{t}\right| \right)}+C$$

$$$\int \left(- \frac{1}{t}\right)\, dt = - \ln\left(\left|{t}\right|\right) + C$$$A