Integral dari $$$a l t \left(x - \pi\right) \cos{\left(x \right)}$$$ terhadap $$$x$$$
Kalkulator terkait: Kalkulator Integral Tentu dan Tak Wajar
Masukan Anda
Temukan $$$\int a l t \left(x - \pi\right) \cos{\left(x \right)}\, dx$$$.
Solusi
Terapkan aturan pengali konstanta $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ dengan $$$c=a l t$$$ dan $$$f{\left(x \right)} = \left(x - \pi\right) \cos{\left(x \right)}$$$:
$${\color{red}{\int{a l t \left(x - \pi\right) \cos{\left(x \right)} d x}}} = {\color{red}{a l t \int{\left(x - \pi\right) \cos{\left(x \right)} d x}}}$$
Untuk integral $$$\int{\left(x - \pi\right) \cos{\left(x \right)} d x}$$$, gunakan integrasi parsial $$$\int \operatorname{u} \operatorname{dv} = \operatorname{u}\operatorname{v} - \int \operatorname{v} \operatorname{du}$$$.
Misalkan $$$\operatorname{u}=x - \pi$$$ dan $$$\operatorname{dv}=\cos{\left(x \right)} dx$$$.
Maka $$$\operatorname{du}=\left(x - \pi\right)^{\prime }dx=1 dx$$$ (langkah-langkah dapat dilihat di ») dan $$$\operatorname{v}=\int{\cos{\left(x \right)} d x}=\sin{\left(x \right)}$$$ (langkah-langkah dapat dilihat di »).
Jadi,
$$a l t {\color{red}{\int{\left(x - \pi\right) \cos{\left(x \right)} d x}}}=a l t {\color{red}{\left(\left(x - \pi\right) \cdot \sin{\left(x \right)}-\int{\sin{\left(x \right)} \cdot 1 d x}\right)}}=a l t {\color{red}{\left(\left(x - \pi\right) \sin{\left(x \right)} - \int{\sin{\left(x \right)} d x}\right)}}$$
Integral dari sinus adalah $$$\int{\sin{\left(x \right)} d x} = - \cos{\left(x \right)}$$$:
$$a l t \left(\left(x - \pi\right) \sin{\left(x \right)} - {\color{red}{\int{\sin{\left(x \right)} d x}}}\right) = a l t \left(\left(x - \pi\right) \sin{\left(x \right)} - {\color{red}{\left(- \cos{\left(x \right)}\right)}}\right)$$
Oleh karena itu,
$$\int{a l t \left(x - \pi\right) \cos{\left(x \right)} d x} = a l t \left(\left(x - \pi\right) \sin{\left(x \right)} + \cos{\left(x \right)}\right)$$
Sederhanakan:
$$\int{a l t \left(x - \pi\right) \cos{\left(x \right)} d x} = - a l t \left(\left(\pi - x\right) \sin{\left(x \right)} - \cos{\left(x \right)}\right)$$
Tambahkan konstanta integrasi:
$$\int{a l t \left(x - \pi\right) \cos{\left(x \right)} d x} = - a l t \left(\left(\pi - x\right) \sin{\left(x \right)} - \cos{\left(x \right)}\right)+C$$
Jawaban
$$$\int a l t \left(x - \pi\right) \cos{\left(x \right)}\, dx = - a l t \left(\left(\pi - x\right) \sin{\left(x \right)} - \cos{\left(x \right)}\right) + C$$$A