bonjour
E = X⁴ - 6 x² + 8 = 0
X ² - 6 x + 8 = 0
Δ = 36 - 4 ( 1 * 8 ) = 36 - 32 = 4 = 2²
x 1 = ( 6 - 2 ) / 2 = 4/2 = 2
x 2 = ( 6 + 2 ) /2 = 4
x² = 2 ⇔ x = √ 2 ou - √ 2
x²= 4 ⇔ x = √4 ou - √ 4 ⇔ x = 2 ou - 2
S ( √2 ; - √2 ; - 2 ; 2 )
X ⁴ - 2 x² - 8 = 0
X² - 2 x - 8 = 0
Δ = 4 - 4 ( 1 * - 8 ) = 4 + 32 = 36 = 6 ²
x 1 = ( 2 - 6 ) / 2 = - 4 /2 = - 2
x 2 = ( 2 + 6 ) /2 = 4
x² = - 2 ⇔ pas de solutions
x² = 4 ⇔ x = √4 ou - √4 ⇔ x = 2 ou - 2
S ( - 2 ; 2 )
allez fais le dernier
