Integralen av $$$\frac{75}{u^{3}}$$$

Bestäm $$$\int \frac{75}{u^{3}}\, du$$$.

Tillämpa konstantfaktorregeln $$$\int c f{\left(u \right)}\, du = c \int f{\left(u \right)}\, du$$$ med $$$c=75$$$ och $$$f{\left(u \right)} = \frac{1}{u^{3}}$$$:

$${\color{red}{\int{\frac{75}{u^{3}} d u}}} = {\color{red}{\left(75 \int{\frac{1}{u^{3}} d u}\right)}}$$

Tillämpa potensregeln $$$\int u^{n}\, du = \frac{u^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ med $$$n=-3$$$:

$$75 {\color{red}{\int{\frac{1}{u^{3}} d u}}}=75 {\color{red}{\int{u^{-3} d u}}}=75 {\color{red}{\frac{u^{-3 + 1}}{-3 + 1}}}=75 {\color{red}{\left(- \frac{u^{-2}}{2}\right)}}=75 {\color{red}{\left(- \frac{1}{2 u^{2}}\right)}}$$

Alltså,

$$\int{\frac{75}{u^{3}} d u} = - \frac{75}{2 u^{2}}$$

Lägg till integrationskonstanten:

$$\int{\frac{75}{u^{3}} d u} = - \frac{75}{2 u^{2}}+C$$

$$$\int \frac{75}{u^{3}}\, du = - \frac{75}{2 u^{2}} + C$$$A