Integral de $$$f \left(x + \frac{1}{x}\right)$$$ con respecto a $$$x$$$
Calculadora relacionada: Calculadora de integrales definidas e impropias
Tu entrada
Halla $$$\int f \left(x + \frac{1}{x}\right)\, dx$$$.
Solución
Expand the expression:
$${\color{red}{\int{f \left(x + \frac{1}{x}\right) d x}}} = {\color{red}{\int{\left(f x + \frac{f}{x}\right)d x}}}$$
Integra término a término:
$${\color{red}{\int{\left(f x + \frac{f}{x}\right)d x}}} = {\color{red}{\left(\int{\frac{f}{x} d x} + \int{f x d x}\right)}}$$
Aplica la regla del factor constante $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ con $$$c=f$$$ y $$$f{\left(x \right)} = x$$$:
$$\int{\frac{f}{x} d x} + {\color{red}{\int{f x d x}}} = \int{\frac{f}{x} d x} + {\color{red}{f \int{x d x}}}$$
Aplica la regla de la potencia $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ con $$$n=1$$$:
$$f {\color{red}{\int{x d x}}} + \int{\frac{f}{x} d x}=f {\color{red}{\frac{x^{1 + 1}}{1 + 1}}} + \int{\frac{f}{x} d x}=f {\color{red}{\left(\frac{x^{2}}{2}\right)}} + \int{\frac{f}{x} d x}$$
Aplica la regla del factor constante $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ con $$$c=f$$$ y $$$f{\left(x \right)} = \frac{1}{x}$$$:
$$\frac{f x^{2}}{2} + {\color{red}{\int{\frac{f}{x} d x}}} = \frac{f x^{2}}{2} + {\color{red}{f \int{\frac{1}{x} d x}}}$$
La integral de $$$\frac{1}{x}$$$ es $$$\int{\frac{1}{x} d x} = \ln{\left(\left|{x}\right| \right)}$$$:
$$\frac{f x^{2}}{2} + f {\color{red}{\int{\frac{1}{x} d x}}} = \frac{f x^{2}}{2} + f {\color{red}{\ln{\left(\left|{x}\right| \right)}}}$$
Por lo tanto,
$$\int{f \left(x + \frac{1}{x}\right) d x} = \frac{f x^{2}}{2} + f \ln{\left(\left|{x}\right| \right)}$$
Simplificar:
$$\int{f \left(x + \frac{1}{x}\right) d x} = \frac{f \left(x^{2} + 2 \ln{\left(\left|{x}\right| \right)}\right)}{2}$$
Añade la constante de integración:
$$\int{f \left(x + \frac{1}{x}\right) d x} = \frac{f \left(x^{2} + 2 \ln{\left(\left|{x}\right| \right)}\right)}{2}+C$$
Respuesta
$$$\int f \left(x + \frac{1}{x}\right)\, dx = \frac{f \left(x^{2} + 2 \ln\left(\left|{x}\right|\right)\right)}{2} + C$$$A