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  • Deprecated function: Optional parameter $account declared before required parameter $entity_type is implicitly treated as a required parameter in include_once() (line 1442 of /home/senemav/www/includes/bootstrap.inc).
  • Deprecated function: Optional parameter $account declared before required parameter $entity_type is implicitly treated as a required parameter in include_once() (line 1442 of /home/senemav/www/includes/bootstrap.inc).
  • Deprecated function: Optional parameter $input declared before required parameter $form_state is implicitly treated as a required parameter in include_once() (line 1442 of /home/senemav/www/includes/bootstrap.inc).

BFEM

BFEM Mathématiques 2017

Exercice 1  (5 points)

On donne trois réels $a$, $b$ et $c$ tels que: $a=7-5\sqrt{2}\, b\,=\,-7-5\sqrt{2}\ $ et $\ c\,=\,-7+5\sqrt{2}$

1) Démontre que le réel $a$ est l'inverse du réel $b$.          (1 point)

2) Justifie que a et c sont opposé.       (1 point)

3) Démontre que $\dfrac{b}{a}-\dfrac{c}{b}=b^2+c^2$.        (1 point)

4) Calcule $a^2$ puis déduis-en une écriture simplifiée du réel $w=\sqrt{99-70\sqrt{2}}$       (2 points)