Réponses

2012-09-23T21:04:52+02:00

A=√(6+2√5)-√(6-2√5)

A² = (√(6+2√5)-√(6-2√5))²

= 6+2√5 - 2√[(6+2√5) * (6-2√5)] + (6-2√5)

= 6+2√5 - 2√(6² - 4*5) + 6-2√5

= 12 - 2√(36 - 20)

= 12 - 2√16

= 12 - 2*4

= 12 - 8

= 4

 

En espérant t'avoir aidé.