Express the Product as a Sum Containing Only Sines or Cosines

question 10

Multiple Choice

Express the product as a sum containing only sines or cosines.
- $$\cos \frac { 11 \theta } { 2 } \cos \frac { \theta } { 2 }$$

• A) \(\frac { 1 } { 4 } \cos ^ { 2 } ( 5 \theta )\)
• B) \(\frac { 1 } { 4 } [ \cos ( 6 \theta ) - \sin ( 4 \theta ) ]\)
• C) \(\frac { 1 } { 2 } [ \cos ( 2 \theta ) + \cos ( 3 \theta ) ]\)
• D) \(\frac { 1 } { 2 } [ \cos ( 3 \theta ) - \sin ( 2 \theta ) ]\)

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Definitions:

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A difference between two groups or variables that is unlikely to have occurred due to chance alone, as determined by statistical analysis.

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The number of observations or elements selected from a population to be included in a statistical sample.

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