81 Bài tập Phương trình lượng giác đủ dạng

Ph­¬ng tr×nh l­îng gi¸c-PDT
1/. T×m xÎ (0; 2p) cña pt : 
2/. sin23x - cos24x = sin25x - cos26x
3/. T×m x Î [0;14] : cos3x - 4cos2x + 3cosx - 4 = 0 . 
4/. cosx+ cos2x + cos3x + cos4x + cos5x = -1/2
5/.(cos2x - 1)(sin2x + cosx + sinx) = sin22x
6/.5sinx - 2 = 3(1 - sinx)tg2x
7/.cotgx - 1 = + sin2x - sin2x
8/.cotgx - tgx + 4sin2x = 
9/.
10/.
10/.
12/. cos23xcos2x - cos2x = 0
13/. 1 + sinx + cosx + sin2x + cos2x = 0
14/. cos3x + cos2x - cosx - 1 = 0
15/.
16/.cotx + sinx(1+tanx.tanx/2) = 4
17/.
18/. 2sin22x + sin7x - 1 = sinx
19/.
20/.T×m m: cã Ýt nhÊt mét nghiÖm thuéc ®o¹n 
21/. 
22/. 
23/. tgx + cosx - cos2x = sinx(1 + tgxtgx/2) 
24/. 25/.
26/. 
27/. cos2x + cosx(2tg2x - 1) = 2 29/. sin(pcosx) = 1
30/. 
31/. 32/. 
33/. 
34/. 35/. 
36/.Cho PT: (2) (a lµ tham sè)
a) Gi¶i a =1/3. b) T×m a ®Ó ph­¬ng tr×nh (2) cã nghiÖm ?
37/.Cho ph­¬ng tr×nh: 
 1) Gi¶i m = 1. 2) m=? ®Ó PT cã nghiÖm/. 
38/. 39/.
40/. 41/. 
42/.Cho ph­¬ng tr×nh: 
 1) Gi¶i m = 6. 2) m=? ®Ó PT cã ®óng 2 ng PB/. 
43/. 
43/.A/. 
44/. 45/.
46/. 47/.tg2x + cotgx = 8cos2x
48/. 49/.
50/. sinx.cosx + cosx = -2sin2x - sinx + 1
51/. sin3x = cosx.cos2x.(tg2x + tg2x)
52/. 53/. 
54/. 
55/. 
56/. 57/. 
58/. GBL: 2m(cosx + sinx) = 2m2 + cosx - sinx + 3/2
59/. 
60/. 61/. 
62/. cos2x + cos4x + cos6x = cosxcos2xcos3x + 2
63/. cosx + cos2x + cos3x + cos4x = 0
64/. sin4x + cos2x + 4cos6x = 0
65/. sinx + sin2x + sin3x + sin4x = cosx + cos2x + cos3x + cos4x 
66/.sin3x.cos3x + cos3x.sin3x = sin34x 
67/. 2tgx + cotg2x = 2sin2x + 1/sin2x
68/. cosx.sinx + 
69/.cos7x - tm: 
70/.9sinx + 6cosx - 3sin2x + cos2x = 8 71/. 3(cotgx - cosx) - 5(tgx - sinx) = 2
72/. 73/. tgx + 2cotg2x = sin2x
74/.2cosxcos2x = 1 + cos2x + cos3x 75/. 3sinx + 2cosx = 2 + 3tgx 
76/. sin3x.cos3x + cos3x.sin3x = sin34x
77/
78/.T×m nghiÖm: sinxcos4x + 2sin22x = 1 - 4 tm : 
79/.(1 + tgx)(1 + sin2x) = 1 + tgx 
80/.2sin3x - sinx = 2cos3x - cosx + cos2x 
81/.sinx + cosx + cos2x - 2sinx.cosx = 0