Use a Half-Angle Formula to Find the Exact Value Of \cos

question 17

Essay

Use a half-angle formula to find the exact value of $\cos \frac { \pi } { 8 }$ .

---

Definitions:

Biceps Femoris

A muscle of the thigh that is part of the hamstring group, involved in knee flexion and thigh extension.

Tensor Fasciae Latae

A muscle of the thigh involved in stabilizing the hip and knee during movements.

Sternocleidomastoid

A neck muscle that facilitates the bending and turning of the head.

Orbicularis Oculi

A muscle surrounding the eye socket that controls the closing of the eyelid.