bonsoir
donc le 60
E = 9 - ( 2 x - 1 ) ²
E = 9 - ( 4 x² - 4 x + 1 )
E = 9 - 4 x² + 4 x - 1
E = - 4 x² + 4 x + 8
E ) ( 3 + 2 x - 1 ) ( 3 - 2 x + 1 )
E = ( 2 x + 2 ) ( - 2 x + 4 )
E = 2 ( x + 1 ) ( - x + 2 )
pour x = 1/3
E = 2 ( 1/3 + 3 /3) ( - 1/3 + 6 /3)
e = 2 ( 4 /3 ) ( 5 /3)
E = 2 * 20/9 = 40 /9
