Use a Calculator to Find the Value of the Expression $\cos ^ { - 1 } \left( - \frac { \sqrt { 2 } } { 5 } \right)$

question 68

Multiple Choice

Use a calculator to find the value of the expression rounded to two decimal places.
- $\cos ^ { - 1 } \left( - \frac { \sqrt { 2 } } { 5 } \right)$

• A) \(1.86\)
• B) \(106.43\)
• C) \(- 0.29\)
• D) \(- 16.43\)

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Definitions:

Overt Observation

A research method where the subjects are aware that they are being observed, which can impact their behavior but also adheres to ethical transparency.

Participant Observation

A qualitative research method involving the researcher immersing themselves in a group or community to observe behaviors and interactions firsthand.

Researcher Reactivity

A phenomenon where the presence or behavior of the researcher influences the subjects' behavior, potentially biasing the study results.

Hawthorne Effect

A phenomenon where individuals alter their behavior due to their awareness of being observed as part of a study.