PHƯƠNG TRÌNH LƯỢNG GIÁC Giải các phương trình sau: 1. 4cos 2 5x cos 2 3x + 2(8sinx-1)cosx = 5 (D - 2010) 2. (sin2x+cos2x)cosx + 2cos2x - sinx = 0 (B - 2010) 3. x x xxx cos 2 1 tan1 4 sin)2cossin1( = + +++ π (A - 2010) 4. 3 cos5x - 2sin3xcos2x - sinx = 0 (D - 2009) 5. sinx + cosxsin2x+ 3 cos3x = 2(cos4x+ sin 3 x) (B - 2009) 6. ( ) ( )( ) 3 sin1sin21 cossin21 = −+ − xx xx (A - 2009) 7. 2sinx(1+2cos2x)+ sin2x = 1 + 2cosx (D - 2008) 8. sin 3 x - 3 cos 3 x = sinxcos 2 x - 3 sin 2 xcosx (B - 2008) 9. −= − + x x x 4 7 sin4 2 3 sin 1 sin 1 π π (A - 2008) 10. 2cos3 2 cos 2 sin 2 = + + x xx (D - 2007) 11. 2sin 2 2x + sin7x - 1 = sinx (B - 2007) 12. (1 + sin 2 x)cosx + (1 + cos 2 x)sinx = 1 + sin2x (A - 2007) 13. cos3x + cos2x - cosx - 1 = 0 (D - 2006) 14. 4 2 tantan1sincot = ++ x xxx (B - 2006) 15. ( ) 0 sin22 cossinsincos 2 66 = −+ − x xxxx (A - 2006) 16. cos 4 x + sin 4 x + cos − 4 π x sin − 4 3 π x - 2 3 = 0 (D - 2005) 17. 1 + sinx + cosx + sin2x + cos2x = 0 (B - 2005) 18. cos 2 3xcos2x - cos 2 x = 0 (A - 2005) 19. (2cosx - 1)(2sinx + cosx) = sin2x - sinx (D - 2004) 20. 5sinx - 2 = 3(1 - sinx)tan 2 x (B - 2004) 21. 0 2 costan 42 sin 222 = − − x x x π (D - 2003) 22. cotx - tanx + 4sin2x = x2sin 2 (B - 2003) 23. cotx - 1= xx x x 2sin 2 1 2sin tan1 2cos −+ + (A - 2003) 24. cos3x - 4cos2x + 3cosx - 4 = 0 (D - 2002) 25. sin 2 3x - cos 2 4x = sin 2 5x - cos 2 6x (B - 2002) 26. 5 32cos 2sin21 3sin3cos sin += + + + x x xx x (A - 2002) 27. 2sin2x - cos2x = 7sinx + 2cosx - 4 (ĐHQGHN - 2001) 28. cos3xcos 3 x - sin3xsin 3 x = cos 3 4x + 4 1 (ĐHNNHN - 2001) 29. sin2x + 2tanx = 3 (ĐHBKHN - 2001) 30. sin 4 x + sin 4 (x + 4 π ) + sin 4 (x - 4 π ) = 8 9 (ĐHGTVT - 2001) 31. 48 - xx sincos 24 21 − (1+cot2xcotx) = 0 (ĐHMĐC - 2001) 32. sin += − 2 3 10 sin 2 1 210 3 xx ππ (ĐHThủy lợi - 2001) 33. sin2x - cos2x = 3sinx +cosx - 2 (ĐHNN1 - 2001) 34. 4sin 3 xcos3x + 4cos 3 xsin3x + 3 3 cos4x = 3 (HVCNBCVVT - 2001) 35. tan 2 xcot 2 2xcot3x = tan 2 x - cot 2 2x + cot3x(ĐH Luật - 2001) 36. x x tan2 sin 2 2 2 + + 5tanx + 5cotx + 4 = 0 (ĐH TM - 2001) 37. sin 4 2 x + cos 4 2 x = 1 - 2sinx (ĐH Công đoàn - 2001) 38. cos + 4 2 π x + cos − 4 2 π x + 4sinx = 2 + 2 (1 - sinx) (ĐH Hàng hải - 2001) 39. sin2x + 2cos2x = 1 + sinx - 4cosx (ĐH An ninh 2001) 40. 2cos2x + sin 2 xcosx + cos 2 xsinx = 2(sinx + cosx) (ĐHDL PĐ - 2001) 41. sin 2 x + sin 2 2x + sin 2 3x = 2 (ĐHSP TPHCM) 42. cos3x + x3cos 2 2 − = 2(1 + sin 2 2x) (HVNH TPHCM) 43. sin 4 x + cos 4 x = sin2x - 2 1 44. 4sin 3 x + 4sin 2 x + 3sin2x + 6cosx = 0 . PHƯƠNG TRÌNH LƯỢNG GIÁC Giải các phương trình sau: 1. 4cos 2 5x cos 2 3x + 2(8sinx-1)cosx = 5 (D - 2010) 2. (sin2x+cos2x)cosx