466 



PRACTICAL MATHEMATICS 



(22) C = 0-0002596 sin (50002-3-798) (23) -{3 sin 0-sin 30} 



V 



(24) {10-15 cos 20+6 cos 40 -cos 60} 

 82 



(25) ~{cos 50+5 cos 30 + 10 cos 0} 



(26) {cos 60+6 cos 40 + 15 cos 20+10} 

 82 



(27) -^-{3 sin 20 -sin 60} (28) -^{cos 80 - 4 cos 40 +3} 

 82 



(29) ---{6 sin 20+2 sin 40-2 sin 60 -sin 80} 

 128 



(30) i{cos 60-2 cos 40 -cos 20 + 2} 



88 



V (pages 77, 78) 



(1) 9-110, 109 14', 56 42', 140 13' 



(2) 6-170, 70 6', 56 33', 40 23' 

 (8) 7-174, 116 30', 44 42', 57 4' 



(4) 15-59, 86 19', 134 53', 45 7' 



(5) 3-952, 61 16', 127 24', 50 46' (6) 7-668 



(7) 4-123, 5-477, 5-916, 10-88, 74 33', 42 13', 63 14' 



(8) 59 33', 4-952 



(9) (1) 2, - 1, 2, 0-8166, 65 54', 144 45', 65 54', 0-333, - 0'667, 

 0-333. (2) 5, 4, - 6, 2-771, 56 20', 46 9', 117 30', 1-535, 

 1-919, - 1-279. (3) 2, 3, 4, 1-536, 39 49', 59 12', 67 25', 

 1-1805, 0-787, 0-5902 



(10) 9 18' (11) |, - 2, 5 ; 2, * - ; Yes (12) 0-7588 



(13) 4-801, 62 41', 60 (14) 2-305, 4-335, 5-265 (15) 42 33' 



VI (pages 97, 98) 



(1) e^'cosx (2) 



cos x sin x 



2VI 



(5) 



x x* 



(7) # 2 (3 sin x + x cos x] 



(3) cot x (4) x cos x + sin x 



(6) cosec x(l x cot x} 



(8) x^e? (x + 3) 

 / 



log e 



(9) *-i(l + n log e x) (10) a-n-i^- 



(11) x*(x tan 2 x + 4 tan x + x) (12) a; 71 - 1 (a? cot x+ nlog e sin x) 



