Use the Sum-To-Product Formulas to Select the Sum or Difference $\cos 3 \theta + \cos 6 \theta$

question 27

Multiple Choice

Use the sum-to-product formulas to select the sum or difference as a product.
$\cos 3 \theta + \cos 6 \theta$

• A) \(2 \cos \frac { 9 \theta } { 2 } \cos \left( - \frac { 3 \theta } { 2 } \right)\)
• B) \(2 \cos \frac { 9 \theta } { 2 } \sin \left( - \frac { 3 \theta } { 2 } \right)\)
• C) \(2 \cos \frac { 9 \theta } { 2 } \cos \left( \frac { 3 \theta } { 2 } \right)\)
• D) \(2 \cos \left( - \frac { 9 \theta } { 2 } \right) \cos \frac { 3 \theta } { 2 }\)
• E) \(2 \cos \frac { 9 \theta } { 2 } \sin \left( \frac { 3 \theta } { 2 } \right)\)

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Definitions:

Personal Territories

Areas or spaces individuals consider their own, often marked and defended against intrusions by others.

Emergent Norm Theory

Collective behaviour is regulated by norms based on distinctive behaviour that arises in the initially normless crowd.

Norm-Governed Behaviour

Actions or behaviors that are regulated by the norms or rules of a society or group, ensuring compatibility and cohesion within the group.

Collective Action

Activities or efforts undertaken by a group of people with the aim of achieving a common goal.