Question

principal value of cos inverse cos 680

Answer 1

We write this mathematically as follows :

Cos ⁻¹ { Cos 680°) }

Cos ⁻¹ {Cos (4π - 40°) }

4π = 360 × 2 = 720

720 - 40 = 680°

Cos ⁻¹ {Cos (4π - 40)}

= Cos ⁻¹ (Cos 40) = 40

= 40°.

Answer 2

HEY HERE IS YOUR ANSWER......

We write this mathematically as follows:

Cos -1 {Cos 680°)}
Cos -1 {Cos (4 pie - 40°)}
4pie = 360 × 2 = 720
720 - 40 = 680°

Cos -1 {Cos (4pie - 40)}
= Cos -1 (Cos 40) = 40

= 40°

HOPE IT HELPS....