Use a Double-Angle Formula or Half-Angle Formula to Simplify $\cos ^ { 2 } \frac { \pi } { 8 } - \sin ^ { 2 } \frac { \pi } { 8 }$

question 114

Essay

Use a double-angle formula or half-angle formula to simplify $\cos ^ { 2 } \frac { \pi } { 8 } - \sin ^ { 2 } \frac { \pi } { 8 }$ .

---

Definitions:

Hibernation

Long-term torpor in response to winter cold and scarcity of food. Compare with estivation.

Basking

Basking is a behavior observed in various animals, especially reptiles, where individuals expose themselves to sunlight or another heat source to regulate body temperature.

Cancer Risk

The probability of developing cancer over a certain period, influenced by genetic factors, lifestyle choices, and environmental exposures.

Decrease Risk

A strategy or action taken to reduce the likelihood of facing potential threats or negative outcomes.