bonsoir
f (x) = x² - 6 x - 7
α = - b / 2 a
α = 6 / 2 = 3
β = 3² - 6 *3 - 7 = 9 - 18 - 7 = - 16
f (x) = ( x - 3 )² - 16
f ( x) = x² + x + 7
α = - 1 /2
β = ( - 1 /2 )² - 1/2 + 7 = 1/4 - 2/4 + 28/4 = 27/4
f (x) = ( x + 1/2 )² + 27/4
essaie de poursuivre
