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					Bµi 1 : Gi¶i c¸c ph-¬ng tr×nh sau
1. cos2x  3sin x  2 ;2. 4sin4 x  12cos2 x  7 ;                3.     25sin2 x  100cos x  89
                                                     sin6 x  cos6 x 1
4.     sin4 2x  cos4 2x  sin2x cos2x         ;5.                   tan2x
                                                     cos2 x  sin2 x 4
           3
6. tan2 x     9            ,7,2sin2x – cos2x            - 4sinx + 2 = 0;8,9cos2x - 5sin2x -
         cos x
5cosx + 4 = 0
                                                                                           
9)       5sinx(sinx - 1) - cos2x = 3;10)cos2(3x +                        ) – cos23x – 3cos(   -
                                                                       2                    2
3x) + 2 = 0
11;cos2x + sin2x + 2cosx + 1 = 0;12;                         3cos2x + 2(1 +           2 + sinx)sinx –
(3 + 2 ) = 0
                                                         3
13, tg2x + ( 3 - 1)tgx –               3 = 0;14)                       3 cot gx  3
                                                             sin 2 x
    4 sin 2 2 x  6 sin 2 x  9  3 cos 2 x             cos x(cos x  2 sin x)  3 sin x(sin x  2 )
15;                                          0 ;16;                                                   1
                     cos x                                                sin 2 x  1
Bai 2Chuyªn §Ò PT bËc nhÊt ®èi víi Sin vµ cos
1)    3 cos 3x  sin 3x  2 ;2, cos 7 x cos 5 x  3 sin 2 x  1  sin 7 x sin 5 x
                                     2 6
3;T×m c¸c nghiÖm x  ( ; ) cña PT: cos 7 x  3 sin 7 x   2
                                      5 7
4) 2 2 (sin x  cos x) cos x  3  cos 2 x ;
Bai 3:Chuyªn §Ò : PT ®cÊp bËc 2 ®èi víi sin vµ cos
1) sin2x + 2sinxcosx + 3cos2x - 3 = 0 ;2)                                      sin2x – 3sinxcosx + 1 = 0
3) 4 3 sinxcosx + 4cos2x = 2sin2x + 5/2
                                5                                3
4) 3 sin 2 (3  x)  2 sin(         x) cos(  x)  5 sin 2 (  x)  0
                                 2            2                      2
                                                 1                                  1
5)[§HAN_98]a. 3 sin x  cos x                        ;b. 4 sin x  6 cos x 
                                              cos x                              cos x
         2                                     2
6) cos x – 3sinxcosx – 2sin x – 1 = 0
7) 6sin2x + sinxcosx – cos2x = 2
                  Bai 4:Chuyªn §Ò 8: PTLG §xøng ®èi víi sin2n vµ cos2n
1)[§HBKHN_96]               sin4x + cos4x = cos2x;2)[§H HuÕ_99]                             sin6x + cos6x = 7/16
                                 1
3) sin6x + cos6x = sin 2 2 x ;4) sin6x + cos6x = cos4x
                                  4
5)[HVCTQG TPHCM_00]:16(sin6x + cos6x – 1) + 3sin6x = 0
                                                   13                                        x           x
6)[§HQG_98] cos6x – sin6x =                           cos22x;7)[§HC§_01] sin 4 ( )  cos 4 ( )  1  2 sin x
                                                    8                                        2           2
Bai 5: Chuyªn §Ò 9:                     sö dông ct h¹ bËc
1. sin x  sin 3x  cos 2 x  cos 2 4 x
        2         2           2
                                                                       3. sin 2 x  sin 2 2 x  sin 2 3x  0
                                     3                                                                 17
2. sin 2 x  sin 2 2 x  sin 2 3 x                                        4; . sin8 x  cos8 x  cos2 2 x
                                     2                                                                 16
5) cos2x + cos22x + cos23x = 3/2;6) cos2x + cos22x + cos23x = 1
7)[§H HuÕ] sin2x + sin22x + sin23x = 3/2 ;8)[§HY_98] sin23x – sin22x –
sin2x = 0
9)[§HQG_98] sin2x = cos22x + cos23x
10)[§H_B02]sin23x – cos24x = sin25x – cos26x ;11)cos2x + cos22x + cos23x +
cos24x = 2
12) cos2x + cos22x + cos23x + cos24x = 3/2
 C – Ph-¬ng tr×nh biÕn ®æi vÒ tÝch
Bµi 6 : Gi¶i ph-¬ng tr×nh
1 . cos x  cos 2 x  cos3 x  cos 4 x  0 ;2. cos x  cos3x  2cos5 x  0
3) sinx + sin2x + sin3x = 1 + cosx + cos2x ;4)     sinx + sin2x + sin3x =
             cosx + cos2x + cos3x
5)[§H N«ng L©m TPHCM_01]:1 + cosx + cos2x + cos3x = 0
6)[HVQHQT_99]    cosx + cos2x + cos3x + cos4x = 0
7)[§HSP Vinh_97] sinx + sin2x + sin3x + sin4x + sin5x + sin6x = 0
8)[§H §µ N½ng_B97] sin3x – sinx + sin2x = 0
7) cos10x – cos8x – cos6x + 1 = 0 ;8)[HVQHQT_00] cosx + cos3x + 2cos5x
= 0
9)[§HNTHN_97] 9sinx + 6cosx – 3sin2x + cos2x = 8
10)[§HNT TPHCM_00]1 + sinx + cos3x = cosx + sin2x + cos2x
12) (2sinx – 1)(2sin2x + 1) = 3 – 4cos2x
13)[§HYHN_96] (cosx – sinx)cosxsinx = cosxcos2x
14)[§HHH_00] (2sinx + 1)(3cos4x + 2sinx – 4) + 4cos2-x = 3
15)[§H §µ N½ng_99] cos3x – sin3x = sinx – cosx
16)[§H Thuû S¶n Nha Trang_96] cos3x + sin3x = sinx – cosx
17)[§HCSND_00] cos3x + sin3x = sin2x + sinx +cosx
18)[HVQY_00] cos2x + sin3x + cosx = 0
19)[HVNH_99] cos3x + cos2x + 2sinx – 2 = 0
20)[HVNH TPHCM_00] sinx + sin2x + cos3x = 0
21)[HVBCVT TPHCM_97] cos2x – 4sinxcosx = 0
Chuyªn §Ò 13: sd CT biÕn ®æi tÝch thµnh tæng
1) cos11x.cos3x = cos17x.cos9x
2) sin18x.cos13x = sin9x.cos4x
3) sin2x + sin2xsin4x + sin3xsin9x + sin4xsin16x = 1
4) (sinx + 3 cosx)sin3x = 2

				
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posted:11/22/2011
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