Integral de $$$s \sin{\left(10 x \right)}$$$ em relação a $$$x$$$

Encontre $$$\int s \sin{\left(10 x \right)}\, dx$$$.

Aplique a regra do múltiplo constante $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ usando $$$c=s$$$ e $$$f{\left(x \right)} = \sin{\left(10 x \right)}$$$:

$${\color{red}{\int{s \sin{\left(10 x \right)} d x}}} = {\color{red}{s \int{\sin{\left(10 x \right)} d x}}}$$

Seja $$$u=10 x$$$.

Então $$$du=\left(10 x\right)^{\prime }dx = 10 dx$$$ (veja os passos »), e obtemos $$$dx = \frac{du}{10}$$$.

Portanto,

$$s {\color{red}{\int{\sin{\left(10 x \right)} d x}}} = s {\color{red}{\int{\frac{\sin{\left(u \right)}}{10} d u}}}$$

Aplique a regra do múltiplo constante $$$\int c f{\left(u \right)}\, du = c \int f{\left(u \right)}\, du$$$ usando $$$c=\frac{1}{10}$$$ e $$$f{\left(u \right)} = \sin{\left(u \right)}$$$:

$$s {\color{red}{\int{\frac{\sin{\left(u \right)}}{10} d u}}} = s {\color{red}{\left(\frac{\int{\sin{\left(u \right)} d u}}{10}\right)}}$$

A integral do seno é $$$\int{\sin{\left(u \right)} d u} = - \cos{\left(u \right)}$$$:

$$\frac{s {\color{red}{\int{\sin{\left(u \right)} d u}}}}{10} = \frac{s {\color{red}{\left(- \cos{\left(u \right)}\right)}}}{10}$$

Recorde que $$$u=10 x$$$:

$$- \frac{s \cos{\left({\color{red}{u}} \right)}}{10} = - \frac{s \cos{\left({\color{red}{\left(10 x\right)}} \right)}}{10}$$

Portanto,

$$\int{s \sin{\left(10 x \right)} d x} = - \frac{s \cos{\left(10 x \right)}}{10}$$

Adicione a constante de integração:

$$\int{s \sin{\left(10 x \right)} d x} = - \frac{s \cos{\left(10 x \right)}}{10}+C$$

$$$\int s \sin{\left(10 x \right)}\, dx = - \frac{s \cos{\left(10 x \right)}}{10} + C$$$A