bonsoir
20 x² + 290 x + 600 = 90 000
20 x² + 290 x + 600 - 90 000 = 0
20 x² + 290 x - 89 400 = 0
Δ = 84 100 - 4 ( 20 * - 89 400) = 84 100 + 7152000 = 7 236 100
x 1 = ( - 290 - 2 690 ) / 40 = - 2 980 /40 = - 74.5
x 2 = ( - 290 + 2 690 ) / 40 = 2400 /40 = 60
v ( 60) = 20 *60² + 290*60 + 600 = 72 000 + 17 400 + 600 = 90 000
v ( - 74.5) = 20 * ( - 74.5)² + 290 * - 74.5 + 600 = 111 005 - 21 605 + 600
= 90 000
