Tích phân hay

P

pipi_hihi

P

passingby

Mấy bài trong đề dự bị..mọi ng cùng làm nha

[TEX]\int_{0}^{ln3}\frac{{e}^{x}dx}{\sqrt{{({e}^{x}+1)}^{3}}}[/TEX]


[TEX]\int_{0}^{\frac{\pi }{2}}\sqrt[6]{1-{cos}^{3}x}.sinx.{cos}^{5}xdx[/TEX]

[TEX]\int_{0}^{\frac{\pi }{4}}\frac{xdx}{1+cos2x}[/TEX]
1. Đặt : [TEX]u=e^x+1 \Rightarrow du=e^xdx[/TEX]
\Rightarrow[TEX]I=\int_{}^{}\frac{du}{\sqrt{u^3}}[/TEX]
\Leftrightarrow[TEX]I=\frac{-1}{2\sqrt{u}}[/TEX]
......Thế cận .
2. Đặt : [TEX]\sqrt[6]{1-{cos}^{3}x} =u \Leftrightarrow 2u^5du=cos^2xsinxdx[/TEX]
\Leftrightarrow [TEX]I=\int_{}^{}2(u^6-1)u^{11}du[/TEX]
......
3. [TEX]I=\frac{1}{2}\int_{}^{}\frac{xdx}{cos^2x}[/TEX]
Đặt [TEX]u=x\Leftrightarrow du=dx[/TEX]; [TEX]dv=\frac{dx}{cos^2x} \Leftrightarrow v= tanx[/TEX]
\Rightarrow[TEX]I=xtanx +\int_{}^{}\frac{d(cosx)}{cosx}[/TEX]
.............
 
Last edited by a moderator:
Top Bottom