APPENDIX 



457 



32. 

 33. 

 34. 

 35. 

 36. 

 37. 



38. 



39. 



40. 

 41. 



42. 



43. 



APPENDIX D 

 Simple Trigonometric Formulas 



n- 

 n- 



since sin 



cos x = 



sin-x -f cos'x = 1 

 sec l a; = 1 + tan 2 *: 



sjn (x + i/) = sin .r cos y + cos x sin y 

 . sin ( x y) = - / cos x sin y 



cos (x + J/) = cos x cos t/ sin .r sin // 

 cos (x y) = cos x cos y + sin x sin y 

 tan x + tan y 



tan 



tan (x y) = ' 



1 tan a- tan // 

 tan a: tan y 



sin 2x 

 cos 2x 



tan 2.r 



tan j- tan y 

 2 sin x cos x 

 cos 2 x sin 2 J? 



n X 

 1 - tan'z 



a 



sin .1 



Loto o/ Sines. 

 In ant/ triangle 



sin 



sin ( 



Law of Cosines. In any triangle the square of any side is equal to the 

 sum of the squares of the other two sides minus twice the product of these 

 dM into the cosine of their included angle. 



Thn 



44. a 2 - 6* + c j - 2bc cos A 



c - a* 



a fe 8 



45. cos A = 







47. 



00,0--'^. 



