Question

How do you use a calculator to evaluate `sec((12pi)/5)`?

Answer 1

3.24

Explanation:

`sec ((12pi)/5) = sec ((2pi)/5 + (10pi)/5) = sec ((2pi)/5 + 2pi) =`
`= sec ((2pi)/5) = 1/cos((2pi)/5)`
Find `cos ((2pi)/5) = cos (360/5) = cos 72^@` by calculator.
`cos 72^@ = 0.31`
There for:
`sec ((12pi)/5) = 1/0.31 = 3.24`

Answer 2

sec 7.539822369 or cos 0.132629119

Explanation:

sec `(12pi/5)`

= `sec(37.69911184/5)`

=`sec7.539822369`

=`cos0.132629119`