Plane trigonometry, by S.L. Loney.

86 TRIGONOMETRY. [Exs. XII.
5. 4cos0-3sec0=2tan. 6. sin2 0-2 cos 0+-=0.
4
7. tan2 - (1+ 3) tan 0 +3 =0.
8. cot208+ (/3 + 3 cot0+1=O.
9. cot -abtan =a-b. 10. tan20+cot2O=2.
11. see0 - = (/2- 1)tan. 12. sin50=
i=/2
13. sin 90= sin 0. 14. sin 30= sin 20.
15. cosm0 =cos nO. 16. sin 20=cos30.
17. cos 50 = cos 40. 18. cos m0= sin nO.
19. cot 0 =tan 80. 20. cot 0 = tan 0.
21. tan 20 = tan. 22. tan 20 tan 0= 1.
23. tan2 30 = cot2 a. 24. tan 30= cot 0.
25. tan2 30= tan2 a. 26. 3 tan2 0 = 1.
27. tan?x + cot a = 0. 28. tan (r cot 0) = cot (r tan 0).
1 1
29. sin(0 - )=, and cos (0 + )=.
1 /3
30. cos(2x +3y)=2, cos(3x+22y)=.
31. Find all the angles between 0~ and 90~ which satisfy the equation
sec2 0 cosec2 0 + 2 cosec2 0 = 8.
32. If tan2 0=, find versin 0 and explain the double result.
331 f the coversin
33. If the coversin of an angle be, find its cosine and cotangent.