Bài tập Tích phân hay
Nguyễn Phú Khánh – ðà Lạt lại ( ) ( ) ( ) ( ) P x dx x a x b x c− − −∫ ðặt : ( ) ( ) ( ) ( ) ( ) ( ) ( ) , , . P x A B c A B C x a x b x c x a x b x c = + + ⇒ − − − − − − ( )( )∫ −− dx bxax xP 3 )( ðặt : ( ) ( ) ( ) ( )3 2 3 ( ) , , , P x A B C D A B C D x a x bx a x b x b x b = + + + ⇒ − −− − − − ( ) ( ) 1 1 1 1 1 ln x dx dx C x x xx x α α β α β α β βα β − = − = + − − − − −− − ∫ ∫ ( ) ( )2 2 1 1 1 1 1 1 ln 2 2 x a dx dx dx C a x a x a ax a x ax a x a − = = − = + − +− +− + ∫ ∫ ∫ 1 3 2 2 2 2 ( 2) ( 2) ( 2) 3 x dx x d x x C− = − − = − +∫ ∫ ( ) 122 ( 3) ( 3) 3( 3) dx x d x x C x −−= + + = − + + +∫ ∫ 2 2 2 21 1( ) 2 2 x x xxe dx e d x e C= = +∫ ∫ 1 11 22 3 3 3 3 33 3 3 3 1 1 (1 ) 1 (1 ) (1 ) (1 ) 3 3 1 21 1 3 x dx x x d x C x C x − + − + = + + = + = + + + − + ∫ ∫ 2 1 32 2 3 33 3 3 2 1 2 2 2 2 3 3 3 3 x dx x dx x dx x x C x x C x − + = + = + + = + + ∫ ∫ ∫ ( ) ( ) ( )1 13 cos - 2 sin - 2 3 cos 2 - sin 2x x x dx x dx x dx x dx dx x x + = + − + ∫ ∫ ∫ ∫ ∫ 23 sin 2 cos lnx x x x C= + − + + 1 1 cos 8 cos2 sin 3 cos5 (sin 8 sin2 ) ( ) 2 2 8 2 x x x xdx x x dx C= − = − + +∫ ∫ ( ) 4 2 2 2 sin 1 1 3 1 cos 2 tan 2 cos2 2 tan sin2 2 4 2 4cos cos x dx dx x dx x x xd x x x x C x x = + − = − + + = − + + ∫ ∫ ∫ ∫ ( ) ( ) ( )cos 13 sin 2 1 3. sin 2 1 2 1 sin 2 xdx cotx x dx x d x x − + = − + + ∫ ∫ ∫ ( ) ( )sin 3 3sin 2 1 2 1 ln | sin | cos(2 1) sin 2 2 d x x d x x x C x = − + + = + + +∫ ∫ Nguyễn Phú Khánh – ðà Lạt 1 1 1 1 3 3(3 cos 3 ) 3 cos 3 3 sin 3 sin 3 3 ln 3 ln 3 x x x xx dx xdx dx x C x C − −− = − = − + = − +∫ ∫ ∫ ( ) ( ) 1 1 ln 1 1 1 1 x x x x x x d ed x e d x d x x e C e e e + = − = − = − + + + + + ∫ ∫ ∫ ∫ Tính nguyên hàm của các hàm số sau : 3 1 1 ( )f x x x = − ( ) 2 3x xf x = + ( ) = + − +( 1)( 1)f x x x x ( ) = − −37 5 1 1 ( )( )f x x x x x ( ) = + + 22 cos2 2 sin 3f x x x x ( ) = + + +2 12 sin 2 cosf x x x x x Tìm nguyên hàm ( )F x của hàm số ( ) − −= 3 2 2 1x x f x x biết ( )− =3 10F ( ) = + + 22 cos2 2 sin 3f x x x x biết π = − 3 3 F Tính nguyên hàm bằng phương pháp ñổi biến số ðịnh lý : Cho hàm số ( )= u u x có ñạo hàm liên tục trên K và hàm số ( )= y f u liên tục sao cho ( ) f u x xác ñịnh trên K . Khi ñó nếu F là một nguyên hàm của f , tức là ( ) ( )= +∫ f u du F u C thì ( ) ( ) = + ∫ f u x dx F u x C 2 1 dx I x x = + ∫ ðặt : 2 2 21 1t x t x td t xdx= + ⇒ = + ⇒ = ( ) 222 2 2 1 1 1 2 1 1111 1 dx xdx tdt dt I dt t ttt tx x x x = = = = = − − +−− + + ∫ ∫ ∫ ∫ ∫ 2 2 1 1 1 1 1 ln ln 2 1 2 1 1 t x I C C t x − + − = + = + + + + ( )32 2 . 1 1 xdx I x x = + + + ∫ Nguyễn Phú Khánh – ðà Lạt ðặt : 2 2 2 2 2 1 1 1 11 . 1 1 xdx tdt dt t x t x tdt xdx t t tx x = + ⇒ = + ⇒ = ⇒ = = + ++ + + 22 1 2 1 1 . 1 dt I t C x C t = = + + = + + + + ∫ Tính nguyên hàm của các hàm số sau 5(5 3)x dx+∫ ( )202 1x dx+∫ ( ) 1 2 21 x xdx+∫ 3 3 3 1 4x x dx x + ∫ 2 1 4 4 dx x x− +∫ 2 1 6 9 dx x x− +∫ ( )3 1 2 3 dx x + ∫ 2 3 9 1- x dx x ∫ 2 1 (1 ) dx x x+ ∫ 2 2 3 3(8 27) x dx x + ∫ 2 3 2 6 9 x dx x x + + +∫ 3 2 2 3 2 x dx x x x + + −∫ 23 2 3 x x dx x + + +∫ 2 4 5 2 x x dx x + + +∫ 3 2 2 1 x dx x x+ +∫ 2 2 3 3 3 3 2 x x dx x x + + − +∫ 2 3 2 3 1 2 5 6 x dx x x x + − − +∫ 4 21x x dx−∫ 43 21x x dx−∫ 2 1 5 6 dx x x− +∫ 2 1 1 dx x x− ∫ 2 ln 3x dx x + ∫ . ln . ln(ln ) dx x x x∫ 5ln dx x x ∫ 1 1x dx e +∫ 2 2 1 x x e dx e +∫ 21 x x e dx e−∫ 21 x dx e+ ∫ 6 0 sin .sin 4 .x x dx π ∫ cos sinxe xdx∫ s in cosxe xdx∫ 3 cos sinxe xdx∫ Nguyễn Phú Khánh – ðà Lạt ( )ln 3 ln ex dx x x+∫ 4x x dx e e−−∫ 2x xe e dx−+ +∫ 3 4 cos sin x dx x ∫ 4cos xdx∫ ( )2 4tan tanx x dx+∫ 1 sin 1 cos x dx x + −∫ 4sin xdx∫ 6cos xdx∫ 2 2sin cosx xdx∫ 2 5sin cosx xdx∫ 3 2sin cosx xdx∫ 5sin os 3 3 x x c dx∫ 4sin cosx xdx∫ 3 4 sin cos x dx x ∫ 4 6 sin cos x dx x ∫ 4 sin cos x dx x ∫ 5 sin cos x dx x ∫ tanxdx∫ cotxdx∫ 3(tan tan )x x dx+∫ 3(cot + cot )x x dx∫ 3 2 tan cos x dx x ∫ 2 cot 1 sin x dx x+∫ 4cos dx x ∫ 6sin dx x ∫ 6 1 cos dx x ∫ 1 5 4 cos dx x+∫ sin cos dx x x±∫ cos2 1 sin cos x dx x x+∫ sin cos sin2 x x dx x x + ∫ 1 tan 2 1 2 1 x dx x x + + + − ∫ Tính nguyên hàm bằng phương pháp từng phần ðịnh lý : Nếu ,u v là hai hàm số liên tục trên K thì −∫ ∫ ( ) '( ) = ( ) ( ) ( ) '( )u x v x dx u x v x v x u x du 2 2 ln( 1) . 1 x x x I dx x + + = + ∫ 2 2 2 2 ln( 1) ln( 1) . 1 1 x x x x I dx x x dx x x + + = = + + + + ∫ ∫ Nguyễn Phú Khánh – ðà Lạt ðặt : ( )2 2 2 2 2 2 1ln 1 1 . 1 1 1 1 x u x x dxxdu dx x x x xdv dx x v x += + + + = =⇒ + + += + = + ( ) ( )2 2 2 21 ln 1 1 ln 1 .I x x x xdx x x x x C= + + + − = + + + − +∫ Tính nguyên hàm của các hàm số sau s inx xdx∫ (2 1)sinx xdx+∫ sin 3 x x dx∫ -xxe dx∫ ( 1) xx e dx+∫ 3 3 cos 1 1 x dx x + + ∫ e s inx xdx∫ sin2xe xdx∫ lnx xdx∫ 2 lnx xdx∫ 2 1xe dx+∫ 2tanx xdx∫ 2tanx xdx∫ 2ln( )x x dx+∫ 1ln 1 x x dx x − +∫ ( ) 2 3 21 x dx x− ∫ Tích Phân Ví dụ : Nguyễn Phú Khánh – ðà Lạt ( ) 3 3 3 4 4 2 2 2 1 2 3 2 dx d x x x = = = −∫ ∫ 7 7 7 33 3 2 16 3 3 ( 3) ( 3) 3 3 3 x dx x d x x x − = − − = − − = ∫ ∫ 4 4 4 0 0 0 (25 3 ) 2 2 25 3 ( 13 5) 3 325 3 3 25 3 d xdx x x x − − − = = − = − − − − ∫ ∫ ( )21 1 1 2 2 2 0 0 0 12 1 ln 1 ln 3 1 1 d x xx dx x x x x x x + ++ = = + + = + + + +∫ ∫ ( ) ( ) ( ) ( ) ( ) 1 1 1 1 2 2 22 2 2 2 3 3 2 2 2 2 0 0 0 0 1 15 5 5 5 1 35 . . 2 2 2 4 361 1 1 d x xxdx x x x − − − = − = − = = −− − − ∫ ∫ ( ) 5 5 5 5 5 5 55 2 2 2 2 2 2 2 2 1 2 1 1 ( 1 ) 2 2 1 2 ln 1 3 4 ln 2 1 1 1 1 x dx dx dx dx dx d x x x x x x x + = − + = − + = − − − = − − − = − − − − − −∫ ∫ ∫ ∫ ∫ ∫ ( ) ( ) ( ) ( ) 4 4 4 4 2 3 3 3 3 21 2 1 1 4 ln ln 1 2 1 33 2 1 2 xx x dxdx dx x x xx x x x −− − − − = = + = = − − −− + − − ∫ ∫ ∫ 0 0 0 2 1 1 1 1 1 1 1 3 1 3 ln ln 2 3 1 2 1 2 24 3 dx x dx x x xx x− − − − = − = = − − −− + ∫ ∫ 11 1 1 20 0 0 0 2 ln 2 ln 2 ln 3 2 24 xdx dx dx x x x xx = + = + + − = + −−∫ ∫ ∫ ( ) ( ) 11 1 1 20 0 0 0 3 2 1 20 1 1 ln 1 20 ln 6 ln2 20 ln 5 10 ln 6 7 1 6 7 75 6 x dx dx dx x x x xx x + = + = + + − = + − + −− − ∫ ∫ ∫ 4 4 4 4 4 4 4 4 sin (cos ) tan ln 0 x d x xdx dx cosx cos x cosx π π π π π π π π − − − − − = = = − =∫ ∫ ∫ ( ) 2 2 2 2 2 4 4 4 1 1 1 4sin cot xdx dx cotx x x π π π π π π π = − = − − = − ∫ ∫ ( ) 23 3 3 2 2 2 4 4 4 3 3 2 11 3 3 tan 2 5 3cos cos sin cot x dx dx x cotx x x x π π π π π π − = − = + = − ∫ ∫ ( ) 3 3 3 2 2 2 2 6 6 6 1 1 4 3 tan 3sin cos sin cos dx dx x cotx x x x x π π π π π π = + = − = ∫ ∫ 2 2 2 3 3 3 2 9 0 0 0 1 1 1 . ( ) (1 ) 2 2 2 x x xx e dx e d x e e− − − − − = − = = − −∫ ∫ Nguyễn Phú Khánh – ðà Lạt 32 2 2 1 1 1 ( 2) 2 ln(2 ) ln 2 12 2 xx x x x d e e ee dx e ee e −− − + + = = + = ++ +∫ ∫ 2 2 2(ln ) ln ln ln2 ln ln e e e e e e dx d x x x x x = = =∫ ∫ 4 5 4 1 1 1 ln (ln ) 1 (ln ) (ln ) 5 5 e e e x x dx x d x x = = =∫ ∫ . Ngoài ra , ta có thể ñặt lnt x= ( ) ( ) 1 2 2 1 2 2 2 2 2 1 2 1 1 1 1 5 2 2 x x x dx x dx x dx x x − − − − − − − + = − − + + = − − + + = ∫ ∫ ∫ 2 25 5 5 5 1 5 1 1 1 1 1 2 (1 ) 1 1 4 1 1 1 1 x x x x x dx dx dx dx x x x x x − − − − − − − − − − − + − − − = = = = = − − − −∫ ∫ ∫ ∫ 1 2 2 1 2 3 3 2 2 2 0 0 1 10 1 (1 ) ( 1) ( ) 2 3 3 x x x dx x dx x dx x x − = − + − = − + − = ∫ ∫ ∫ 3 4 4 3 4 3 2 3 2 2 2 2 0 0 3 0 3 49 6 ( 6) ( 6) 6 6 3 2 3 2 3 x x x x x x dx x x dx x x dx x x − − = − + + + − − = − + + + − − = ∫ ∫ ∫ ( ) 2 2 0 20 0 2 cos cos cos sin sin 2x dx xdx x dx x x π π π π π π π = + − = − =∫ ∫ ∫ 2 2 2 0 0 0 1 cos2 2 sin 2 sin sin 4 2xdx x dx xdx xdx π π π π π − = = − = ∫ ∫ ∫ ∫ 2 0 0 0 2 1 cos2 cos cos cos 2 2 x dx x dx xdx xdx π π π π π + = = − =∫ ∫ ∫ ∫ ( ) 0 2 2 sin2 . 2 sin x I dx xπ− = + ∫ ðặt : sin cost x dt xdx= ⇒ = ðổi cận 0 0 1 2 x t x t π = ⇒ = = − ⇒ = − Nguyễn Phú Khánh – ðà Lạt ( ) ( ) ( ) ( ) ( ) 0 0 0 2 2 2 1 1 1 2 2 1 2 2 2 2 2 22 2 2 ttdt I dt d t tt t t− − − + − = = = − + ++ + + ∫ ∫ ∫ ( ) 0 1 2 2 ln 2 2 ln2 2. 2 I t t − = + + = − + 8 2 3 1 dx x x + ∫ ðặt : 2 2 1 1 x xdx tdt t x dt dx dx t xx = + ⇒ = = ⇒ = + ðổi cận 3 2 8 3 x t x t = ⇒ = = ⇒ = ( ) 222 2 2 1 1 1 2 1 1111 1 dx tdt tdt dt dt t ttt tx x x x = = = = − − +−− + + ( ) 338 3 2 2 23 2 1 1 1 1 1 1 1 3 ln 1 ln 1 ln ln . 2 1 1 2 2 1 2 21 dx t dt t t t t tx x − − = − − + = = − + + + ∫ ∫ 1 2 0 1 dx x x+ +∫ 2 2 1 31 2 4 x x x + + = + + ðặt ( )22 1 3 3 1 3 1 3 tan ; tan 1 tan 2 4 2 2 4 2 2 2cos x t t dx d t dt t dt t π π + = ∈ − ⇒ = − = = + ðổi cận 1 0 tan 63 1 tan 3 3 x t t x t t π π = ⇒ = ⇒ = = ⇒ = ⇒ = Nguyễn Phú Khánh – ðà Lạt Vậy ( ) ( ) 2 1 3 3 2 20 6 6 3 1 tan 2 3 32 3 3 91 1 tan 4 t dt dx dt x x t π π π π π + = = = + + + ∫ ∫ ∫ 1 4 2 0 . 4 3 dx x x+ +∫ ( ) ( )4 2 2 22 2 1 1 1 1 1 24 3 1 31 3x x x xx x = = − + + + ++ + 1 1 1 4 2 2 2 0 0 0 1 24 3 1 3 dx dx dx A B x x x x = − = + + + + + ∫ ∫ ∫ 1 2 0 1 dx A x = +∫ ðặt : ( ) ( ) 2 2 2 2 1 tan tan , 1 tan 2 2 1 1 tan t dtdx x t t dx t dt dt x t π π +− = < < ⇒ = + ⇒ = = + + ðổi cận 0 0 1 4 x t x t π = ⇒ = = ⇒ = 4 4 0 0 4 A dt t π π π = = =∫ 1 2 0 3 dx B x = +∫ ðặt : ( ) ( ) 2 2 2 2 1 tan1 1 3 tan , 3 1 tan 2 2 1 1 tan3 3 t dtdx x t t dx t dt dt x t π π +− = < < ⇒ = + ⇒ = = + + ðổi cận 0 0 1 6 x t x t π = ⇒ = = ⇒ = 6 6 0 0 1 1 3 3 6 3 B dt t π π π = = =∫ 1 4 2 0 1 . 2 44 3 6 3 dx x x π π = − + + ∫ Nguyễn Phú Khánh – ðà Lạt 1 0 , 0I x x a dx a= − >∫ 1a• ≥ khi ñó 1 1 3 2 0 0 1 ( ) . 3 2 2 3 x ax a I x x a dx − = − − = + = −∫ 0 1a• < < khi ñó 1 1 3 2 3 2 0 0 ( ) ( ) 3 2 3 2 a a a a x ax x ax I x x a dx x x a dx − = − − + − = + + − ∫ ∫ 3 3 3 3 ... 3 2 cos2 cos 3 sin x dx x x π π − ∫ Nguyễn Phú Khánh – ðà Lạt 3 6 1 sin2 cos2 sin cos x x dx x x π π + + +∫ 2 4 4 0 cos2 .(cos sin ).x x x dx π +∫ ( ) 2 10 10 4 4 0 cos sin cos sinx x x x dx π + −∫ 2 0 sin 7 cos 6 4 sin 3 cos 5 x x dx x x π + + + +∫ 3 6 1 sin sin 6 dx x x π π π + ∫ Tính tích phân bằng phương pháp từng phần Công thức tích phân từng phần : = −∫ ∫( ) '( ) ( ) ( ) ( ) '( ) b b b a a a u x v x dx u x v x v x u x dx Dạng 1 β α ∫ sin ( ) ax ax f x cosax dx e ðặt = = ⇒ = = ∫ ( ) '( ) sin sin cos ax ax u f x du f x dx ax ax dv ax dx v cosax dx e e Dạng 2: β α ∫ ( )ln( )f x ax dx ðặt = = ⇒ = = ∫ ln( ) ( ) ( ) dx u ax du x dv f x dx v f x dx Ví dụ : 2 1 ln e A x xdx= ∫ 1 2 0 xB x e dx= ∫ 4 4 1 lnI x xdx= ∫ 2 0 sinJ x xdx π = ∫ 2 1 ln e A x xdx= ∫ ðặt: 2 3 ln 3 dx duu x x dv x dx x v = = ⇒ = = 3 3 3 3 3 3 2 2 1 11 1 1 1 2 1 ln = ln 3 3 3 9 3 9 9 e e e e x e x e e e A x xdx x x dx − + = − = − = − =∫ ∫ 1 2 0 xB x e dx= ∫ Nguyễn Phú Khánh – ðà Lạt ðặt 2 2 xx du xdxu x v edv e dx == ⇒ == 1 1 1 1 2 2 0 0 0 0 2 2 ,x x x xB x e dx x e xe dx e C C xe dx= = − = − =∫ ∫ ∫ ðặt x x u x du dx dv e dx v e = = ⇒ = = 1 1 1 0 0 0 2 2 2x x xB e xe e dx e e e = − − = − + = − ∫ 4 4 1 lnI x xdx= ∫ ðặt: 4 5 1 ln 5 du dxu x x dv x dx x v = = ⇒ = = 5 5 5 55 5 5 4 1 1 11 1 1 1 3124 . ln . 625 ln 5 625 ln 5 625 ln 5 5 5 5 5 5 25 x x x I x dx x dx x = − = − = − = − ∫ ∫ 2 0 sinJ x xdx π = ∫ ðặt: sin cos u x du dx dv xdx v x = = ⇒ = = − ( ) 2 2 2 2 0 0 0 0 cos cos cos sin 1J x x x dx xdx x π π π π = − − − = = =∫ ∫ ln2 0 xI xe dx−= ∫ ( ) 1 2 0 ln 1J x x dx= +∫ ln2 0 xI xe dx−= ∫ ðặt: x x u x du dx dv e dx v e− − = = ⇒ = = − ( ) ( ) ( ) ln 2 ln2 ln2ln2 ln2 0 0 0 0 1 1 1 1 ln2. ln2 ln2 2 2 2 2 x x x xI xe e dx e e d x e− − − − −= − − − = − − − = − − = −∫ ∫ ( ) 1 2 0 ln 1J x x dx= +∫ Nguyễn Phú Khánh – ðà Lạt ðặt: ( ) 2 2 2 2 ln 1 1 1 2 xdx duu x x dv xdx v x = = + +⇒ = = ( ) ( ) 1 21 1 1 131 2 2 2 2 2 2 0 0 0 0 00 11 1 1 1 1 . ln 1 ln 2 ln 2 2 2 2 2 21 1 1 d xx x J x x dx xdx dx x x x x + = + − = − + = − + + + +∫ ∫ ∫ ∫ ( ) 1 2 0 1 1 1 1 1 1 1 ln2 ln 1 ln2 ln2 ln2 2 2 2 2 2 2 2 J x= − + + = − + = − . 2 0 (2 1)cosI x xdx π = −∫ 1 ln e e J x dx= ∫ 2 0 (2 1)cosI x xdx π = −∫ ðặt 2 1 2 cos sin u x du dx dv xdx v x = − = ⇒ = = 2 2 2 2 0 0 0 0 (2 1)cos =(2 1)sin2 2 sin 1 2 cos 3I x xdx x x xdx x π π π π π π= − − − = − + = −∫ ∫ 1 ln e e J x dx= ∫ Vì ln 1; ln 1 ln ;1 x khi x e x x khi x e ∈ = − ∈ ( ) 1 1 1 1 1 1 2 ln ln ln ln ... 2 e e e e J x dx xdx xdx xdx e = − + = − = = −∫ ∫ ∫ ∫ ( ) 0 32 1 1xx e x dx − + +∫ 5 cos2 .x x dx π π− ∫ Nguyễn Phú Khánh – ðà Lạt ( ) 4 0 1 cosx xdx π −∫ ( ) 2 0 1 sin2x xdx π +∫ 2 0 ( os )s inx c x xdx π +∫ 4 0 ( sin ) 1 cos x x dx x π + +∫ 3 0 .sin .x x dx π ∫ 4 2 0 cos x dx x π ∫ 3 2 4 tanx xdx π π ∫ 3 2 0 sin cos x x dx x π + ∫ 2 3 4 cos sin x xdx x π π ∫ 3 4 0 tan . cos2 x dx x∫ 4 0 1 cos2 x dx x π +∫ 4 0 cos xdx∫ 2 0 sinx xdx π ∫ 2 4 0 cosx xdx π ∫ ( ) 2 2 0 sin sinx x dx π +∫ 3 6 ( cos sin ).x x dx π π −∫ 4 1 xe dx∫ 2 cos 0 sin2xe xdx π ∫ 2 3 0 sin 5xe xdx π ∫ 2 2 0 cosx xdx π ∫ ( ) 2 2 0 2 1 cosx xdx π −∫ ( ) 4 2 0 sinx x dx π ∫ ( ) 1 2 0 sinxe x dxπ∫ ( )2 1 2 1 sinx xe x e x dx − +∫ 1 9 3 2 5 0 1 5 sin (2 1) 4 1 x x dx x x + + + − ∫ 2 2 0 xxe dx∫ ( ) 1 0 2 xx e dx−∫ ( ) 1 2 0 1 xx e dx+∫ 2 1 3 0 xx e dx∫ ( ) 1 2 2 0 1 xx e dx+∫ ( ) 1 2 2 0 4 2 1 xx x e dx− −∫ 0 2 1 2 2.x x dx − + +∫ 1 2 0 4 x dx−∫ 2 2 sin 3 0 sin cosxe x xdx π ∫ Nguyễn Phú Khánh – ðà Lạt 2 1 3 1 .xx e dx − ∫ 2 ln 2 5 0 xx e dx∫ 1 1 ( )ln e x xdx x +∫ ( )2 1 ln e x x dx∫ 2 1 ( ln ) e x x xdx∫ ( ) 3 2 2 1 ln 1 x x dx x + ∫ 1 cos(ln ) e x dx π ∫ ( ) 2 2 1 sin log x dx π ∫ ( ) 2 0 cos ln 1 cosx x dx π +∫ ( ) 3 2 2 ln x x dx−∫ 1 ln e x xdx∫ ( ) 2 1 2 lnx xdx−∫ 2 1 ln e x xdx∫ 3 2 1 ln e x xdx∫ ( ) 1 2 0 ln 1x x dx+∫ ( ) 3 2 0 ln 5x x dx+∫ 10 2 1 lgx xdx∫ 2 1 ln e x dx x ∫ ( )21 ln 1 e e x dx x + ∫ ( )2 2 1 ln 1 x dx x + ∫ 3 3 1 ln e x dx x ∫ 1 2 0 ln( 1)x x dx+∫ 2 2 1 ln( )x x dx+∫ 1 2 2 1 2 1 . ln . 1 x x dx x − − + ∫ 2 0 2 cos 4x xdx π ∫ ( )3 2 6 ln sin cos x dx x π π ∫ Nguyễn Phú Khánh – ðà Lạt 1 2 2 0 1 1 ln 11 x dx xx + −−∫ ( )23 2 0 ln 1 1 x x x dx x + + + ∫ ( ) 4 3 0 sin cos ln cosx x x dx π ∫ Một số tích phân tổng hợp 3 2 3 sin cos x x dx x π π− ∫ 2 2 0 .cos . 1 sin x x dx x π +∫ 1 2 2 0 ( 1) xx e dx x +∫ ñặt 2 2( 1) xu x e dx dv x = = + ( ) 1 0 1 1 nn n dx x x+ + ∫ 3 8 4 3 2 ( 1) x dx x −∫ ñặt 5 3 4 3( 1) u x x dx dv x = = − ( ) 2 1 3 0 1 2 x xx e dx−−∫ 2 0 1 sin 1 cos xxe dx x π + +∫ ( )1 cos4 0 ln 1 sin 1 cos x x dx x π + + +∫ ( )1 cos2 0 1 sin ln 1 cos x x dx x π + + +∫ 1 1 1 12 2 2 1 22 2 2 2 2 2 2 0 0 0 0 1 (1 ) (1 ) 1 (1 ) dx x x dx x dx dx I I x x x x + − = = − = − + + + +∫ ∫ ∫ ∫ Tính 1 1 2 0 1 dx I x = +∫ bằng phương pháp ñổi biến số Tính 1 2 2 2 2 0 (1 ) x dx I x = +∫ bằng phương pháp từng phần : ñặt 2 2(1 ) u x x dv dx x = = + Nguyễn Phú Khánh – ðà Lạt Tìm 0x > sao cho 1 2 2 0 1 ( 1) xt e dx t = +∫ Dạng ñặc biệt ( ) 1 2 1 ln 2007x x dx − + +∫ ( ) 4 0 ln 1 tanx dx π +∫ 4 42 2 4 4 4 4 0 0 cos . sin . cos sin cos sin x dx x dx x x x x π π = + +∫ ∫ 20092 2009 2009 0 sin sin cos x dx x x π +∫ 20102 2010 2010 0 sin sin cos x dx x x π + ∫ 2 3 4 2 sin 4 5 x dx x− + ∫ 4 3 0 .cos .sinx x xdx π ∫ 2 0 .sin .cosx x xdx π ∫ 2 0 .sin . 1 cos x x dx x π +∫ 20 sin 9 4 cos x x dx x π +∫ 0 1 sin x dx x π +∫ 0 sin 2 cos x x dx x π +∫ 2 0 . sin . 3 cos x x dx x π +∫ 1 2 1 1 . 1 2x x dx − − +∫ 1 2 1 ( 1)( 1) x dx e x− + + ∫ 7 5 34 2 4 3 7 1 cos x x x x dx x π π− − + − + ∫ 2 2 2 cos . 4 sin x x dx x π π − + −∫ 22 2 sin 2 1x x x dx π π− + ∫ 2 2 sin .sin2 .cos5 1x x x x dx e π π− + ∫ 6 64 4 sin cos 6 1x x x dx π π− + +∫ 2sin . 3 1x x dx π π− + ∫ 1 4 1 2 1 x x dx − + ∫ 6 7 8 8 sinx xdx π π− ∫ 1 4 1 . 1 2x x dx − + ∫ 2 2 2 cos 4 sin x x dx x π π− + −∫ 1 4 2 1 1 x dx x x− − + ∫ 3 2 3 1 1 2x x dx − + +∫ 2 2 sin sin 3 cos5 1 x x x x dx e π π − +∫ Nguyễn Phú Khánh – ðà Lạt 2 3 0 7 cos 6 sin (sin cos ) x x dx x x π − +∫ 2 2 2 cos . ln( 1)x x x dx π π− + +∫ 1 2 1 ln( 1 )x x dx − + +∫ 2 0 ( sin cos )x x dx π −∫ Tìm t ñể 4 0 3 4 sin 0 2 t x dx − = ∫ ỨNG DỤNG TÍCH PHÂN Tính diện tích hình phẳng giới hạn bởi các ñường : 3 0 2; 1 y x y x x = = = − = 2 3 0 y x x y = + + = 2 2 1 1 ; sin cos ; 6 3 y y x x x x π π = = = = 2sin 0 y x y x x x π = = + ≤ ≤ sin 2 cos 3 0; y x x y x x π = − = = = 2 3sin .cos y 0 0, 2 y x x x x π = = = = 2( 1) sin 0 x y y x x = + = = 1 x x y e y e x − = = = 2 2 4 y x y x = + = − 2 2 2 y x x y x = + = + 2 2 3 y x x y x = − + = − 2 2 y x x y = = − 2 2 2 6 16 y x x y = + = 2 2 2 2 3 6 0; 4 y x x y x x x x = − = + − = = Nguyễn Phú Khánh – ðà Lạt 2 2 6 0; 1 x y x x x x = − = = 2 2 4 4 4 2 x y x y = − = ( ) 2 2 0 ax y a ay x = > = 2( 1) sin y x x yπ = + = 2 4 5 2 4 4 11 y x x y x y x = − + = − + = − 2 2 2 2 1 2 y x y x x y = = − − = 2 2 6 5 4 3 3 15 y x x y x x y x = − + − = − + − = − 2 2 2 2 4 5 1 y x x y x x y = − + = + + = 2 2 2 4 4 8 y x y x x y = = − − = 2 2 2 2 1 0 0 y x x y y = + + = = 4 0; 1 2 ; 0 1 x x x y y x = = = = − 2 2 8 8 y x x y y x = = = 2 2 27 27 y x x y y x = = = 5( 1) 1 x y x x y e x = + = = 25 0 0; 3 xy y x y x − = = = = − Nguyễn Phú Khánh – ðà Lạt 2 1 2 y x x = − = 2 1 2 x y x = − = 23 2 0 y x x y = − − + = 2 5 6 6 y x x y = − + = 2 4 3 3 y x x y = − + = 2 1 5 y x y x = − = + 2 3 2 2 y x x y = − + = 2 5 6 1 y x x y x = − + = + 2 4 3 3 y x x y x = − + = + 2 4 3 3 y x x y x = − + = − 2 2 1 7 y x y x = − = − + 2 2 3 2y x x y x = − + = − siny x y x π = = − lg 0 1 , 10 10 y x y x x = = = = 2 31 2 sin 2 12 1 0, 2 x y x y x x π π = − = + = = 1 0 y x y x y x e = = = = 2 3 2 (4 ) 4 y x y x = − = 2 2 2 2 27 8( 1) y x y x = = − Nguyễn Phú Khánh – ðà Lạt Thể tích khối tròn xoay ñược tạo bởi khi quay hình phẳng giới hạn bởi các ñường sau quay quanh trục Ox 2y x y x = = 2 10 3 y x y x = = − 2 2 1 1 2 y x x y = + = 2 2 3 4 (4 ) y x y x = = − 4 4cos sin 0 ; 2 y x x y x x π π = + = = = tan 0 0; 3 y x y x x π = = = = Thể tích khối tròn xoay ñược tạo bởi khi quay hình phẳng giới hạn bởi các ñường sau quay quanh trục 1. Ox 2. Oy 2( 2) 4 y x y = − = 22 0 y x x y = − = 2 sin (0 ) 0 y x x y π = ≤ ≤ = 2 1 1 0, 0, 1 y x y x x = + = = = 4 4 0; 2 y x x x = − = = 2 2, 4 4 y x y x y = = = 1 2 0; 0 y x y x y = − = = = . ln 0 1; y x x y x x e = = = = 2( 0) 3 10 1 y x x y x y = > = − + =
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