MATHEMATICS 21 



FUNCTIONS OF 180-A AND OF 180+A 



25. sin (180-A) = sin A 



26. tan (180-A) = -tan A 



27. cos (180-A) = -cosA 



28. cot (180- A) = - cot A 



29. sec (180 - A) = -sec A 



30. esc (180 - A) = esc A 



31. sin (180+A) = -sinA 



32. tan(180+A) = tan A 



33. cos (180+ A) = -cos A 



34. cot (180+ A) = cot A 



35. sec (180+A) = -secA 



36. esc (180+A) = -cscA 



FUNCTIONS OF 360-A AND OF 360+A 



37. sin (360- A) = - sin A 43. sin (360+ A) = sin A 



38. tan (360- A) = -tan A 44. tan (360+ A) = tan A 



39. cos(360-A)= cos A 45. cos (360+ A) = cos A 



40. cot (360- A) = - cot A 46. cot (360+ A) = cot A 



41. sec (360- A) = sec A 47. sec (360+ A) = sec A 



42. esc (360- A) = - esc A 48. esc (360+A) =csc A 



FUNCTIONS OF (A+B) AND OF (A-B) 

 49. sin (A +B) =sin A cos B+cos A sin B 

 60. sin (A B) =sin A cos B cos A sin B 



51. cos (A+JB) = cos A cos B sin A sin B 



52. cos (A B) =cos A cos B+ sin A sin B 



tan A+tan B 



53. tan (A+B) = 



1 tan A tanB 



tan A tan B 



54. tan(A-B) = 



1+tan A tan B 



FUNCTIONS OF 2A AND OF 



55. sin 2A = 2 sin A cos A 



56. cos 2 A = cos 2 A sin 2 A 



57. cos 2A=2 cos 2 A-l 



58. cos 2A = 1-2 sin 2 A 



