bonjour
3 x² + 5 x - 2 = 0
Δ = 25 - 4 ( 3 * - 2 ) = 25 + 24 = 49 = 7 ²
x 1 = ( - 5 - 7 ) / 6 = - 12 /6 = - 2
x 2 = ( - 5 + 7 ) / 6 = 2 /6 = 1/3
solutions = - 2 et 1 /3
3 x² - 6 x + 3 = 0
Δ = 36 - 4 ( 3 * 3 ) = 36 - 36 = 0
Δ = 0 donc 1 seule solution
x 0 = 6 / 6 = 1
x² + x + 1 = 0
Δ = 1 - 4 ( 1 * 1 ) = 1 - 4 = - 3
Δ < 0 donc pas de solutions dans R
