tan^5xdx có a=pi/4 và b=pi/3
Hướng dẫn kỹ dùm mình nha !
[TEX]
\int\limits_{\frac{pi}{4}}^{\frac{pi}{3}} tan^5 x dx
[/TEX]
[TEX]=\int\limits_{\frac{pi}{4}}^{\frac{pi}{3}} tan^5+tan^3 x-tan^3 x+tanx-tanx dx[/TEX]
[TEX]
=\int\limits_{\frac{pi}{4}}^{\frac{pi}{3}} tan^3x(tan^2 x+1)dx-\int\limits_{\frac{pi}{4}}^{\frac{pi}{3}} tanx(tan^2 x +1)dx-\int\limits_{\frac{pi}{4}}^{\frac{pi}{3} }tanxdx
[/TEX]
[TEX]
=(\frac{tan^4x}{4}-\frac{tan^2x}{2} +ln|cosx|) \|_{pi/4}^{pi/3}
[/TEX]
=9/4-1/4-(3/2-1/2)-(ln(1/2)- [TEX](ln(\frac{\sqrt{2}}{2})[/TEX]
=1-ln(1/2)+(ln( [TEX]\frac{\sqrt{2}}{2}[/TEX] )
(mong mấy cô pác coi júp e làm dug chưa nha!!!