Bonjour,
Soient a et b deux réels tels que :
(1+√2)²⁰⁰⁶ =a+b√2
(1 -√2)²⁰⁰⁶ = a - b√2
Calculez a²−2b² :
a²−2b² = a² - (b√2)²
a²−2b² = (a - b√2)(a + b√2)
a²−2b² = (1 - √2)²⁰⁰⁶(1 + √2)²⁰⁰⁶
a²−2b² = [(1 - radic;2)(1 + √2)]²⁰⁰⁶
a²−2b² = (1 - 2)²⁰⁰⁶
a²−2b² = (-1)²⁰⁰⁶ = 1