... x¸c ®Þnh a,b sao cho 1 a cos x bcos xcos x 1 sin x 1 sin x= +− + 3. TÝnh/ 430dx dxI Jcos xcos x π= =∫(§H BK TH_82)4./ 20sin x cos x 1dxsin x 2cosx 3π− ++ +∫(Bé §Ò)5.130(3x ... 203sin x 4cos xdx3sin x 4cos xπ++∫(§H Thuû Lîi_00)33 20x 2x xdx− +∫71./ 40sin x.cosxdxsin2x cos2xπ+∫(§H V¨n Hãa_01D)72./ 22 2 2 20sin x cos xdx a,b 0a cos x b sin ... 1 x dx dxe 1 cos x π++∫ ∫ ∫ (§H QG_98)128. TÝnh 2 2/ 6 / 60 0sin x cos xI dx; J dxsin x 3 cosx sin x 3 cosxπ π= =+ +∫ ∫. Tõ ®ã suy ra: 5 / 33 / 2cos2xdxcosx 3 sin xππ−∫(§H...