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

question 74

Essay

Use a half-angle formula to find the exact value of $\cos \left( - 15 ^ { \circ } \right)$ .

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Definitions:

Experimental Situation

A controlled environment created to test hypotheses and examine the effects of manipulations on variables.

External Validity

The extent to which the results of a study can be generalized to or across populations, settings, times, and other external conditions.

Social Influence

The impact that individuals or groups have on changing the behavior, attitudes, or beliefs of others within a social context.

Analogue Research

A methodology in which subjects are studied in artificially created conditions that approximate real-life scenarios.