Bonjour,
identité remarquables....
(a+b)² = a²+2ab+b²
(a-b)² = a²-2ab+b²
donc :
t² + 18t + 81 = t² + 2(t)(9) + 9² = (t+9)²
x² - 12x + 36 = x² - 2(x)(6) + 6² = (x+6)²
4x² - 4xy + y² = (2x)² - 2(2x)(y) + y² = (2x+y)²
4/9p² + 4/3pq + q² = (2/3p)² + 2(2/3p)(q) + q² = (2/3p+q)²
16y² - 72y + 81 = (4y)² - 2(4y)(9) + 9² = (4y-9)²
π² + 10π + 25 = π² + 2(π)(5) + 5² = (π+5)²
