\hbox\mathrm{Si}~~x=\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+\ldots}}}}~~ \hbox\mathrm{alors}~:
A. x2x – 1 = 0,
B. x2 + x – 1 = 0,
C. x2x + 1 = 0,
D. x2 + x + 1 = 0,
E. x2 – 1 = 0.