CHO HÀM SỐ    SIN .SIN 2 . X X F 2SIN X X D BẰNG

2.3sin .cos 2

dt x xdx

 

3sin 2 .sin

 



2 2

2

1 1

  ^{   }

3

x x f x x f t dt f x dx

sin .sin 2 . 2sin d

 

  

3 3

0 0 0

1 2 1 2

.

1 1 13

   

2x 1

f x dx f x dx dx x dx

       

   

         

3 3 9

   

0 1 0 1