Integral de $$$e^{- a l m x}$$$ con respecto a $$$a$$$

Halla $$$\int e^{- a l m x}\, da$$$.

Sea $$$u=- a l m x$$$.

Entonces $$$du=\left(- a l m x\right)^{\prime }da = - l m x da$$$ (los pasos pueden verse »), y obtenemos que $$$da = - \frac{du}{l m x}$$$.

Entonces,

$${\color{red}{\int{e^{- a l m x} d a}}} = {\color{red}{\int{\left(- \frac{e^{u}}{l m x}\right)d u}}}$$

Aplica la regla del factor constante $$$\int c f{\left(u \right)}\, du = c \int f{\left(u \right)}\, du$$$ con $$$c=- \frac{1}{l m x}$$$ y $$$f{\left(u \right)} = e^{u}$$$:

$${\color{red}{\int{\left(- \frac{e^{u}}{l m x}\right)d u}}} = {\color{red}{\left(- \frac{\int{e^{u} d u}}{l m x}\right)}}$$

La integral de la función exponencial es $$$\int{e^{u} d u} = e^{u}$$$:

$$- \frac{{\color{red}{\int{e^{u} d u}}}}{l m x} = - \frac{{\color{red}{e^{u}}}}{l m x}$$

Recordemos que $$$u=- a l m x$$$:

$$- \frac{e^{{\color{red}{u}}}}{l m x} = - \frac{e^{{\color{red}{\left(- a l m x\right)}}}}{l m x}$$

Por lo tanto,

$$\int{e^{- a l m x} d a} = - \frac{e^{- a l m x}}{l m x}$$

Añade la constante de integración:

$$\int{e^{- a l m x} d a} = - \frac{e^{- a l m x}}{l m x}+C$$

$$$\int e^{- a l m x}\, da = - \frac{e^{- a l m x}}{l m x} + C$$$A