grandes-ecoles 2023 Q1

grandes-ecoles · France · centrale-maths2__official Indefinite & Definite Integrals Integral Inequalities and Limit of Integral Sequences
Show that $$I _ { n } \geqslant \frac { 1 } { 2 ^ { n } }.$$ where $I _ { n } = \int _ { 0 } ^ { 1 } \frac { 1 } { \left( 1 + t ^ { 2 } \right) ^ { n } } \mathrm {~d} t$.
Show that
$$I _ { n } \geqslant \frac { 1 } { 2 ^ { n } }.$$
where $I _ { n } = \int _ { 0 } ^ { 1 } \frac { 1 } { \left( 1 + t ^ { 2 } \right) ^ { n } } \mathrm {~d} t$.