... sin 3x cos3x 2cos2x sin 2x sin 3x+ = có nghiệm là:a. x k8 4π π= +b. x k6 3π π= +c. x k3 2π π= +d. x k4π= + π54. Phươngtrình 3 3 3 3sin x cos x sin x.cot x cos x.tan ... )4 4sin x cos x 1tan x cot xsin 2x 2+= + có nghiệm là:a. x k2π= + πb. x k23π= + πc. x k4 2π π= +d. Vô nghiệm.56. Phươngtrình ( )2 2 sin x cos x .cos x 3 cos 2x+ = +có ... )5 sin x cos x sin 3x cos3x 2 2 2 sin 2x+ + − = + có các nghiệm là:a. x k24π= + π b. x k24π= − + π c. x k22π= + π d. x k22π= − + π62. Cho phươngtrình cos 2x.cos x sin x.cos3x sin...
... ( ) ( )3 22 22 211/ 2cos 2 8cos 7 (1)cos:2cos 1 2cos ( )(1) ;1cos 24 8 5 1 02 32 / 4cos 3tan 4 3 cos 2 3 t anx 4 0(2):2(2) 2cos 3 3 t anx 1 03cos 22 61t anx3x xxDK ... − + + =≠ +⇔ − + + == ⇒ = += Â( )( )2663 / 3 cos cos 1 23 cos cos 1 2 4 cos 1 2(cos 1)2(cos 1) 0;: cos 1 0 cos 1 24 cos 1;x k kx kx xx x x xx xDo x x x k kx xπππππ ... )3 3224 / in os os2 .tan .tan4 4sinx-cos 1 sin x cos os2 sinx-cos 1 sin x cos sinx cos 0sinx-cos 0 sin 04 4sinx cos ( 2)1 sin x cos sinx cos 011 0 2 12S x c x c x x xx x c x x...
... 233 223tan 16 323 2 2tan 32 9 33/ 4sin 3cos 3sin sin cos 0(1)* ét sinx 0 3cos 3 0(1) 4 3cot 3(cot 1) cot 0cot 114cot331cot3kxxx kxx x x x xX xx x xxx kxx kxπ ... )3 3224 / in os os2 .tan .tan4 4sinx-cos 1 sin x cos os2 sinx-cos 1 sin x cos sinx cos 0sinx-cos 0 sin 04 4sinx cos ( 2)1 sin x cos sinx cos 011 0 2 12S x c x c x x xx x c x x ... x xπ ππ ππ ππππ πππ23cos2 8sin 2 .sin 5 01 os22sin 4 3cos 2 8sin 2 . 5 022sin 4 3cos 2 4sin 2 2sin 4 5 03 43cos 2 4sin 2 5 cos 2 sin 2 15 53cos5os(2 ) 1 ;( );42sin5+...
... ( ) ( )3 22 22 211/ 2cos2 8cos 7 (1)cos:2cos 1 2cos ( )(1) ;1cos 24 8 5 1 02 32 / 4cos 3tan 4 3 cos 2 3 t anx 4 0(2):2(2) 2cos 3 3 t anx 1 03cos 22 61t anx3x xxDK ... − + + =≠ +⇔ − + + == ⇒ = ± += Â( )( )2663 / 3 cos cos 1 23 cos cos 1 2 4 cos 1 2(cos 1)2(cos 1) 0;: cos 1 0 cos 1 24 cos 1;x k kx kx xx x x xx xDo x x x k kx xπππππ ... )3 3224 / in os os2 .tan .tan4 4sinx-cos 1 sin x cos os2 sinx-cos 1 sin x cos sinx cos 0sinx-cos 0 sin 04 4sinx cos ( 2)1 sin x cos sinx cos 011 0 2 12S x c x c x x xx x c x x...
... )3 3224 / in os os2 .tan .tan4 4sinx-cos 1 sin x cos os2 sinx-cos 1 sin x cos sinx cos 0sinx-cos 0 sin 04 4sinx cos ( 2)1 sin x cos sinx cos 011 0 2 12S x c x c x x xx x c x x ... 233 223tan 16 323 2 2tan 32 9 33/ 4sin 3cos 3sin sin cos 0(1)* ét sinx 0 3cos 3 0(1) 4 3cot 3(cot 1) cot 0cot 114cot331cot3kxxx kxx x x x xX xx x xxx kxx kxπ ... 08-05 Giải các phươngtrìnhlượnggiác sau: 2 23 32 211/ 2cos 2 8cos 7cos2 / 4cos 3tan 4 3 cos 2 3 t anx 4 03 / 3 cos cos 1 24 / in os os2 .tan .tan4 42 15 / os os (sinx 1)3 3 2x...
... 31 os4 1 os8 1 os2 1 os62 2 2 2cos4 cos8 cos 2 cos64 8 4 8 2 6 2 62cos( )cos( ) 2cos( )cos( )2 2 2 2cos6 cos2 cos2 cos 4cos2 (cos6 cos4 ) 0cos2 0cos6 cos4 0x x x xc x c x c x c xx ... 42 212) 4cos 3 2 sin 2 8cos13) 1 sin sin .cos 2cos cos .sin 014) 1 sin cos cos 2 sin 2 015) 2sin cot 1 2sin 216) cos cos2 cos3 cos4 01 317) sin 2 cos 2 cos 44 418) 1 cos cos cos3 sin ... Thị ðông 36 2 23 2221 cos 2 (2cos 2 1) 3cos 2 02cos 2 3cos 2 cos2 1 01(cos2 ).(2cos 2 2cos2 2) 021cos221cos2 01 5cos2 1222cos 2 2cos 2 21 5cos2 cos23,( )2x x xx x xx...
... x x xxx11sin2 sin 2cot22sin sin2 pt 22 2 2 220x x x xxcos cos cos cossin cos2x = 0 xk42 Bài 5. cos2 5 2(2 cos )(sin cos ) x x x x 1) ... k32 ; 22 Bài 2: 2 2 2 2sin 3 cos 4 sin 5 cos 6x x x x x x x x2 2 2 2sin 3 cos 4 sin 5 cos 6 x x xcos (cos7 cos11 ) 0 kxkx29 ... x x2(cos –sin ) 4(cos – sin ) – 5 0 x k x k222 Bài 6. x x xx3sin2 2sin2sin2 .cos 2(1 cos )sin (2cos 1) 0sin 0, cos 0 x x xxx 2cosx –...
... =+23cos10x 2 cos 4x 6 cos 3x.cos x cos x 8 cos x.cos 3x * Ta co : (*)⇔ ()()3cos10x 1 cos8x cos x 2cos x 4 cos 3x 3cos3x++ = + − ⇔ ()cos10x cos 8x 1 cos x 2 cos x.cos 9x++=+⇔ 2cos ... BC AC ABcos cos cos22BC CA ABcos cos cos cos cos cos22 22 2+++=++22 BC BC AC ACcos cos sin sin cos cos sin sin22 22 22 2BC CAcos cos cos cos22 22−−=+2 ABAcos cos sin sin22 ... 3x cos 2x cos 4x *+=+ Ta co (*) ⇔ ()()()()11111 cos 2x 1 cos6x 1 cos 4x 1 cos 8x2222−+−=+++ ⇔ ()cos2x cos6x cos4x cos8x−+ =+⇔ 2cos 4x cos2x 2 cos 6x cos 2x−=⇔ ()2cos2x cos6x cos4x...