bonjour
C(x) = x² - 20 x + 400
C( 20) = 400 - 400 + 400 = 400
recette = 400 x 30 = 12 000
B = 11 600 €
R = 30 x
B(x) = R (x) - C (x ) = 30 x - ( x² - 20 x + 400) = 30 x - x² + 20 x - 400
B (x) = - x² + 50 x - 400
B ( 10)= 100 + 500 - 400 = 200
B (40) = 1 600 + 2000 - 400 = 3 200
B (x) > 0
- x² + 50 x - 400 = 0
Δ = 2 500 - 4 ( - 1 * - 400)= 2 500 - 1600 = 900 = 30 ²
x 1 = ( - 50 - 30 ) / - 2 = - 80 / -2 = 40
x 2 = ( - 50 + 30 ) / - 2 = - 20 / - 2 = 10
elle réalise des bénéfices au delà de 10 pots
