A) Y = 2(X−1) + 2 + ≥ 2 2(X-1)× 1X-1 +2 =2 2 +2 (0.25) (0.25...

2 . (0.25) Vậy y

min

=2 2 +2 (0.25) b) y

2

= x

2

(4−x

2

)

2

≤ 12 ×(2x

2

+4-x

2

+4-x

2