exo7 1291

Convergence et calcul de : $$\int_{0}^{1}\frac{\ln (1+t^{2})dt}{t^{2}}, \qquad \int_{0}^{\infty }\ln \left( 1+\frac{1}{t^{2}}\right) dt, \qquad \int_{1}^{\infty }\frac{\ln t}{t^{n}}dt.$$