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:

Negativism

denotes a pervasive pattern of negative attitudes, feelings of helplessness and pessimism, or a general opposition to suggestions or advice.

Interactional Synchrony

Describes the coordinated and rhythmic interaction between caregiver and child, facilitating bonding and communication.

Willful

Describing actions or behaviors done intentionally or with a strong determination.

Docile

Easily taught, led, or managed; compliant and submissive.