grandes-ecoles 2011 QVI.C

grandes-ecoles · France · centrale-maths1__psi Indefinite & Definite Integrals Integral Inequalities and Limit of Integral Sequences
For all $i \in \{1,2,3,4\}$, we set $$\theta(N_{i}) = \frac{1}{2N_{i}} + \int_{0}^{+\infty} \frac{h(u)}{(u+N_{i})^{2}} du$$
VI.C.1) Show that for all $i \in \{1,2,3,4\}$ $$0 < \theta(N_{i}) < \frac{1}{N_{i}}$$
VI.C.2) Show the existence of a strictly positive real $K$ such that for all $i \in \{1,2,3,4\}$ $$N_{i} = K e^{\mu \varepsilon_{i}} e^{-\theta(N_{i})}$$
For all $i \in \{1,2,3,4\}$, we set
$$\theta(N_{i}) = \frac{1}{2N_{i}} + \int_{0}^{+\infty} \frac{h(u)}{(u+N_{i})^{2}} du$$

\textbf{VI.C.1)} Show that for all $i \in \{1,2,3,4\}$
$$0 < \theta(N_{i}) < \frac{1}{N_{i}}$$

\textbf{VI.C.2)} Show the existence of a strictly positive real $K$ such that for all $i \in \{1,2,3,4\}$
$$N_{i} = K e^{\mu \varepsilon_{i}} e^{-\theta(N_{i})}$$