A) 1) 0 < x < 3
2) MB'N triangle rectangle en B'
MN² = MB'² + B'N² = 2² + x² = x²+2
MN = racine(x²+2)
3) a. A'N = 3-x
b. NA'S triangle rectangle en A'
c. NS² = A'N² + A'S² = (3-x)² + (3/2)² = x² - 6x + 45/4
NS = racine(x² - 6x + 45/4)
4) L(x) = MN + NS = racine(x²+2) + racine(x² - 6x + 45/4)
5) a. x = 1.5
L(1.5) = 4.18
b. b. A'N = 3 - 1.5 = 1.5
