Réponses

Meilleure réponse !
2014-06-04T15:36:31+02:00
Ex2
1) Ф≈1,618

2) (\frac{1+\sqrt{5}}{2})^{2}=\frac{1+2\sqrt{5}+5}{4}=\frac{6+2\sqrt{5}}{4}

(\frac{1+\sqrt{5}}{2})^{2}=\frac{3+\sqrt{5}}{2}=\frac{1+2+\sqrt{5}}{2}=\frac{1+\sqrt{5}}{2}+1
Donc Ф²=Ф+1

Ex3
a)
(3-\sqrt{2})(3+\sqrt{2})=3^{2}-2=9-2=7

b)
(3-\sqrt{2})(3+\sqrt{2})=7
(3+\sqrt{2})=\frac{7}{(3-\sqrt{2})}

 \frac{(3+\sqrt{2})}{7}=\frac{1}{(3-\sqrt{2})}

\frac{4(3+\sqrt{2})}{7}=\frac{4}{(3-\sqrt{2})}