mot so bai tap luong giac 11

[r]

MỘT SỐ BÀI TẬP LƯỢNG GIÁC 11 Bài 1: Giải phương trình:

1/ cos6x − sin6x=13

8 cos

2

2 x 2/ sin8x+cos8x=17

16 cos

2

2 x

3(sin8x +cos8x )− 6(sin10x+cos10x )=7 cos 2 x

5/ 1+2 cos2 4 x

5 6/ cos

2

x=cos 4 x

3 7/ sin

8

2 x +cos8x =1

8 8/ sin8x+cos8x=2(sin10x+cos10x )+5

4cos 2 x 9/

sin x cot 5 x cos 9 x =1

10/ sin

4

x +cos4x

1

2(tan x+cot x ) 11/

sin x+sin2 x +sin 3 x cos x +cos 2 x+cos 3 x=√3

12/ 3 (cot 2 x +cos 2 x)

cot 2 x −cos 2 x −2 sin 2 x=2 13/

1

tan x +cot 2 x =

√2(cos x −sin x ) cot x −1

14/ sin2x −sin x + 1

sin2x −

1

sin x=0

15/cos2x+cos4x+cos6x=cosxcos2xcos3x+2 16/4cosx-2cos2x-cos4x =1

17/sin4x-cos4x =1+4(sinx-cosx) 21/ (sin x+√3 cos x )sin 3 x=2 18/ cos5

x +sin5x+sin 2 x+cos 2 x =1+√2 22/cotx = tanx+2tan2x 19/

sin x+√2 −sin2x +sin x√2− sin2x=3 23/3(tanx+cotx)=2(2+sin2x) 20/

1

4(sin

10x+cos10x)=sin6x +cos6x

sin22 x+4 cos22 x 24/ cos

2

x+sin3x +cos x =0 25/ cos2

4 x+cos28 x=sin212 x+sin216 x +2 26/3(cotx-cosx)-5(tanx-sinx)=2 27/ tan3x − cot3x −3 (tan2x+cot2x )− 12(tan x − cot x)+8=0

28/ tan3x − cot3x −3 (tan2x+ cot2x )− 3(tan x −cot x)+10=0

29/ 4 (tan2x +cot2x)−4 (tan x −cot x )−7=0 30/

√3(tan2x +cot2x)+2(√3 −1)(tan x − cot x)−4 −2√3=0