Réponses

2014-03-31T15:51:48+02:00
Exercice 1
1.
A = 2V3 + V75 -6V27 (V se lit racine carré de)
A = 2V3 + v(25*3) + -6V(9*3) (* signifie multiplié par)
A = 2V3 +5V3 -6*3V3
A = 7V5 -18V3
A = -11V3

B = (3V12)2
B = (3V(4*3))/2
B = 3*2V3 /2
B = 3V3

2.
C = (3V7-2V5)²
identité remarquable de la forme (a-b)² = a²-2ab+b² avec a = 3V7 et b = 2V5
donc
C = (3V7)² -2*3V7*2V5 +(2V5)²
C = 9*7 - 12V(7*5) +4*5
C = 63 -12V35 +20
C = 83 -12V35

3. x² = 8
2 solutions
x = -V8 et x = V8
x = -V(4*2) et x = V(4*2)
x = -2V2 et x = 2v2