Tài liệu Bài tập phương trình lượng giác luyện thi đh

CHUYÊN ĐỀ: PHƯƠNG GIẢI CÁC PHƯƠNG TRÌNH SAU: 1/ 3sin22x + 7cos2x -3=0 2/ 6cos2x + 5sinx -7=0 3/ cos2x - 5sinx-3 = 0 4/ cos2x + cosx + 1= 0 5/ 7tanx - 4cotx = 12 6/ 4tan4x + 12tan2x = 7 ................................................................................... 7/ 4sinx - 3cosx = 5 8/ 2cos2x + 3sin2x = 3 ................................................................................... 9/ sin2x - 2sinxcosx - 3cos2x = 0 10/ sin2x - 2sin2x = 2cos2x 11/ 6sin2x + sinxcosx -cos2x = 2 .................................................................................. 12/ 2sin3x + 4cos3x = 3sinx 13/ sinxsin7x = sin3xsin5x 14/ cosxcos3x - sin2xsin6x - sin4xsin6x = 0 15/ cosx + cos3x + 2cos5x = 0 16/ co22x + 3cos18x + 3co14x + co10x = 0 ................................................................................. 17/ sin 2 x + sin 2 2 x + sin 2 3 x = 3 / 2 18/ cos 2 x + cos 2 2 x + cos 2 3 x + cos 2 4 x = 2 19/ sin4x+ cos4x = cos4x 20/ sin2xtan2x + cos2xcotx-sin2x = 1+tanx + cotx 21/(2sinx - 1)(2sin2x + 1)= 3 - 4cos2x 3 22/ 3sin 3 x − 3 cos 9 x = 1 + sin x 23/ 2 2(sin x + cos x ) cos x = 3 + cos 2 x 24/ 3sin( x − π π π ) + 4sin( x + ) + 5sin(5 x + ) = 0 3 6 6 3 3 25/ 4 sin x cos 3 x + 4 cos x sin 3 x + 3 3 cos 4 x = 3 1 26/ 3 sin x + cos x = cos x .................................................................................. 27/ 2(sin x + cos x) − sin x cos x = 1 28/ cos x + 1 1 1 + sin x + = cos x sin x 3 29/sin23x - cos24x = sin25x - cos26x 30/ Tìm nghiệm thuộc khoảng (0; 2π ) của PT: 5(s inx+ cos3x+sin3x ) = cos 2 x + 3 1+2sin2x 31/ Tìm x thuộc đoạn [0;14]nghiệm đúng PT: cos3x - 4cos2x + 3cosx - 4 = 0 sin 4 x + cos 4 x 1 1 = cot 2 x − 5sin 2 x 2 8sin 2 x 2 (2 − sin 2 x)sin 3 x 33/ tan 4 x + 1 = cos 4 x 32/ 34/ tanx+cosx-cos2x= sinx(1+tanxtanx/2) 35/ 2 sin x + cos x + 1 1 = sin x − 2 cos x + 3 3 TRÌNH LƯỢNG GIÁC. 1 = sin x 8cos 2 x cos 2 x 1 37/ cot x − 1 = + sin 2 x − sin 2 x 1 + tan x 2 36/ 38/ 3- tanx(tanx+2sinx)+6cosx=0 39/ cos2x+cosx(2tan2x-1) = 2 40/ cotx-tanx+4sin2x=2/sin2x 41/ 3cos4x - 8cos6x + 2cos2x + 3 = 0 42/ 43/ 44/ 45/ 46/ x π (2 − 3) cos x − 2 sin 2 ( − ) 2 4 =1 2 cos x − 1 x π x sin 2 ( − ) tan 2 x − cos 2 = 0 2 4 2 2 cos x(cos x − 1) = 2(1 + sin x) sin x + cos x 2 cos 4 x cot x = tan x + sin 2 x (1 − 2 sin x) cos x = 3 (1 + 2sin x)(1 − sin x) 47/ sin x + cos x sin 2 x + 3 cos 3 x = 2(cos 4 x + sin 3 x) 3 cos 5 x − 2sin 3 x cos 2 x − sin x = 0 49/ (1 + 2sin x) 2 cos x = 1 + sin x + cos x 1 1 7π 50/ + = 4sin( − x) sin x sin( x − 3π / 2) 4 48/