Find the Exact Value of the Expression Using the Provided $\cos ( s + t )$

question 158

Multiple Choice

Find the exact value of the expression using the provided information.
-Find $\cos ( s + t )$ given that $\cos s = \frac { 1 } { 3 }$ , with $s$ in quadrant $I$ , and $\sin t = \frac { 1 } { 4 }$ , with $t$ in quadrant II.

• A) \(- \frac { \sqrt { 15 } + 2 \sqrt { 2 } } { 12 }\)
• B) \(\frac { \sqrt { 15 } - 2 \sqrt { 2 } } { 12 }\)
• C) \(\frac { \sqrt { 15 } - 2 \sqrt { 2 } } { 6 }\)
• D) \(- \frac { \sqrt { 15 } + 2 \sqrt { 2 } } { 6 }\)

---

Definitions:

Norm Salience

Describes the degree to which social norms are noticeable or prominent to individuals in a given context, influencing their behavior.

Jigsaw Classroom Learning Technique

A cooperative learning technique where students are divided into small groups, each learning a different segment of material, then regrouping to share their learning with peers.

Academic Social-networking Technique

Use of social networking strategies and platforms to enhance academic learning and knowledge sharing.

Prosocial Methods

Techniques or approaches that are intended to benefit others, promoting positive social interactions and well-being.