TÌM � X X  2 1  DX 

Câu 2. Tìm � x x

2

1dx ?

A. x

3

  x C . B. 1

4

1

2

2 x � � 3 xx � �  C

4 x  2 xC . C. 2 x C  . D. 1

2

1

3

� � .

3

2

�    � 

2 3 4

x x x ?

x dx