bonjour
f (x) = ( x - 1/3) - ( 3 - x )
f ( -3) = ( - 3 - 1/3 ) - ( 3 +3 ) = - 9/3 - 1/3 = - 10 /3 - 6 = - 10/3 - 18/3 = - 28/3
f ( - 1/2) = ( - 1/2 - 1 /3 ) - ( 3 + 1/2 ) = ( - 3/6 - 2/6 ) - ( 6/2 + 1/2 ) = - 5/6 - 7 /2 = - 5/6 - 21/6 = - 26 /6 = - 13 /3
f (0) = - 1 /3 - 3 = - 1/3 - 9/3 = - 10/3
f ( 2) = ( 2 - 1 /3 ) - ( 3 - 2) = 6/3 - 1/3 - 1 = 5/3 - 3/3 = 2/3
allez finis
