y = x e − 0.4 x x = 0 , x = 1 {\displaystyle y=xe^{-0.4x}~~~x=0,x=1}
∫ 0 5 x e − 0.4 x d x ⏟ {\displaystyle \underbrace {\int _{0}^{5}xe^{-0.4x}dx} }
u = x d v = e − 0.4 x d x d u = d x v = − e − x {\displaystyle {\begin{aligned}u&=x\quad dv=e^{-0.4x}dx\\[2ex]du&=dx\qquad v=-e^{-x}\\[2ex]\end{aligned}}}
![{\displaystyle {\begin{aligned}u&=x\quad dv=e^{-0.4x}dx\\[2ex]du&=dx\qquad v=-e^{-x}\\[2ex]\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/379cbb61d04c27617e187a63d429416aa25b05c2)