Find the value of the following :

(i) cos 62° 27'

(ii) cos 3° 11'

(iii) cos 86° 40'

(iv) cos 45° 58'

(i)

cos 62° 27' = cos (62° 24' + 3')
cos 62° 24' = 0.4633
Mean difference of 3' = .0008       (To be subtracted)
cos 62° 27' = .4633 - .0008 = .4625

Hence, the value of cos 62° 27' = .4625

(ii)

cos 3° 11' = cos (3° 6' + 5')
cos 3° 6' = .9985
Mean difference of 5' = .0001       (To be subtracted)
cos 3° 11' = .9985 - .0001 = .9984

Hence, the value of cos 3° 11' = .9984

(iii)

cos 86° 40' = cos (86° 36' + 4')
cos 86° 36' = .0593
Mean difference of 4' = .0012       (To be subtracted)
cos 86° 40' = .0593 - .0012 = .0581

Hence, the value of cos 86° 40' = .0581

(iv)

cos 45° 58' = cos (45° 54' + 4')
cos 45° 54' = .6959
Mean difference of 4' = .0008       (To be subtracted)
cos 45° 58' = .6959 - .0008 = .6951

Hence, the value of cos 45° 58' = .6951