FORMULAS FOR SINE AND COSINE OF SUM AND DIFFERENCE OF TWO ANGLES ASSIGNMENT 1. Calculate: cos 470 cos17 + sin 470 sin 170; cos 270 cos18 - sin 270 sin 180; sin 28 cos 62 + cos 28 sin 620; sin 83 cos 53 - cos 83 sin 530. 2. Simplify: sin (a + B) - sin (a - B); cos 2a Xcos a + sin2a X sin a; sin 4a Xcos2a - cos4ax sin2a; sin(a+B)cos(a-B)+cos(a+B)sin(a-B). 3. Calculate: cos a + , if sina = - and a e (ST; 2n); sin a - It , if cosa = -202 anda e ; n) 3 4. Calculate: cos (a - B), if cosa = 2, sinB=2 and 0