bonsoir
f (x) = x² - 2 x - 3
f ( 4 √3) = ( 4 √3)² - 2 ( 4 √3) - 3
= 48 - 8 √3 - 3 = 45 - 8 √3
f ( 4 + √3) = ( 4 + √3)² - 2 ( 4 + √3) - 3
= 16 + 8 √3 + 3 - 8 - 2 √3 - 3
= 8 + 6 √3
f ( 3/2) = ( 3/2)² - 2 *3/2 - 3 = 9/4 - 6/2 - 3 = 9/4 - 12/4 - 12/4 = - 15/4
f ( -1) = 1 + 2 - 3 = 0
f ( 3) = 9 - 6 - 3 = 0
f ( -3) = 9 + 6 - 3 = 12 donc non
