Question

Find the value of the following:

cos 74° 39′

Answer 1

0'

6'

12'

18'

24'

30'

36'

42'

48'

54'

Mean difference

0.0°

0.1°

0.2°

0.3°

0.4°

0.5°

0.6°

0.7°

0.8°

0.9°

1

2

3

4

5

6

7

8

49

0.7547

             cos 74° 36′ = 0.2656  ...(From the natural cosines table)
Mean difference 3'  =         8  (−)
          cos 74° 39′     =  0.2648