CÂU 4. Π Π Π Π Π/ 4 / 4 / 4 2 / 4
1 / 4 1 1x x dx xdx x d x x x x xdx
∫ ∫ ∫ ∫
+ = − = − +(1 sin 2 ) cos 2 cos 2 cos 22 2 2 200
0
0
0
π π2
1 / 42
1= + = +sin 2 .32 4 xπ 32 40
0
0
0
π π2
1 / 42
1= + = +sin 2 .32 4 xπ 32 4