scal_009.tex

\exo{Du calcul \dots}
 
\itemitemalph Calculer $\vec v_1 \cdot \vec v_2$ lorsque
$$
   \Vert \vec v_1 \Vert = 3,
      \qquad
   \Vert \vec v_2 \Vert = 8,
      \qquad
   \widehat{(\vec v_1, \vec v_2)} = 120^\circ.
$$
 
\itemitemalph Calculer $\Vert \vec v_2 \Vert$ lorsque
$$
   \Vert \vec v_1 \Vert = 5,
      \qquad
   \vec v_1 \cdot \vec v_2 = 50,
      \qquad
   \widehat{(\vec v_1, \vec v_2)} = {\pi\over3}
$$
 
\itemitemalph Calculer $\widehat{(\vec v_1, \vec v_2)}$ lorsque
$$
   \Vert \vec v_1 \Vert = 15,
      \qquad
   \Vert \vec v_2 \Vert = 8,
      \qquad
   \vec v_1 \cdot \vec v_2 = 60
$$
 
\finexo