Bonjour
E= (4x+1)° + (x-2) (4x+1)
E = (16x² +8x +1) + (4x² +x -8x +2)
E = 16x² +8x +1 + 4x² +x -8x +2
E = 20x² +x +3
1) developper et reduire E
2) factoriser E
E= (4x+1)° + (x-2) (4x+1)
E = (4x+1)(4x+1)+(x-2)
E = (4x+1)(4x+1 +x-2)
E = (4x +1)(5x -1)
3) calculer E pour
si x = 0, E = 0
si x = -1, E = (-4+1)(-5-1) = -3 x -6 = 18
Si x = V2, E = ( 4v2+1)( 5V2-1) = 20V2 -4V2+5V2-1 = -1 +21V2 ;
Si x = 1/5, E = (4x1/5 +1) ( 5x1/5)-1) = (4/5+1)(5/5-1)
E = (4/5 +5/5) x (5/5 -5/5) = 9/5 x 0 = 0
