ĐẶT T= X2−2X+ =2 (X−2+ ≥1 1 1TF’(T)= 3T2 – 4T- 4=0 ⇔T1=-2/3 T2= 2B...

1) - DE + DAP AN THI DH A V
DE + DAP AN THI DH A V
1)Đặt t= x

2

−2x+ =2 (x−1)

2

+ ≥1 1 1tf

’

(t)= 3t

2

– 4t- 4=0 ⇔t

1

=-2/3 t

2

= 2BBTt -2/3 1 2 +∞f

’(t)

0 - 0 +f(t) -1/2 +∞ -4 mf2Từ bảng biến thiờn  = −4