TÌM   X4 X3 X2  X 1  DX 

Câu 3: Tìm x

4

x

3

x

2

  x 1dx ?

5 4 3 2

x x x x

x C

    

5 4 3 2

A. x

5

x

4

x

3

x

2

  x C B.

x

   

C. 4 x

3

 3 x

2

 2 x  1 D.