Question

How do you use a calculator to evaluate `cos78^circ11' 58''`?

Answer 1

0.2046

Explanation:

First, convert 11 minutes an 58 seconds to centum system:

`11' --> (1h(11))/(60) = 18%` --> or 0.18 of an hour.
`58'' --> (1'(58))/(60) = 97%` --> or 0.0097 of an hour

`cos 78^@ 11' 58"" --> cos 78^@1897`

Calculator gives --> `cos 78^@1897 = 0.2046`