

Tính tích phân của
a) [tex]\int_{1}^{e} \frac{cos(lnx)}{cos^2x}dx[/tex]
b) [tex]\int_{0}^{\pi^2} xsin\sqrt{x}dx[/tex]
c) [tex]\int_{0}^{\frac{1}{9}} \frac{x}{sin^2 (2x+1)} dx[/tex]
a) [tex]\int_{1}^{e} \frac{cos(lnx)}{cos^2x}dx[/tex]
b) [tex]\int_{0}^{\pi^2} xsin\sqrt{x}dx[/tex]
c) [tex]\int_{0}^{\frac{1}{9}} \frac{x}{sin^2 (2x+1)} dx[/tex]