Use the sum-to-product formulas to rewrite the sum or difference as a product.
Cos 3θ + cos 8θ

A) $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
B) $2 \cos \frac { 11 \theta } { 2 } \sin - \frac { 5 \theta } { 2 }$
C) $2 \sin \frac { 11 \theta } { 2 } \sin \frac { 5 \theta } { 2 }$
D) $\cos - \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
E) $2 \cos \frac { 11 \theta } { 2 } \cos - \frac { 5 \theta } { 2 }$

Question

Use the sum-to-product formulas to rewrite the sum or difference as a product. ​
Cos 3θ + cos 8θ
​
A)​ $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
B)​ $2 \cos \frac { 11 \theta } { 2 } \sin - \frac { 5 \theta } { 2 }$
C)​ $2 \sin \frac { 11 \theta } { 2 } \sin \frac { 5 \theta } { 2 }$
D)​ $\cos - \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
E) $2 \cos \frac { 11 \theta } { 2 } \cos - \frac { 5 \theta } { 2 }$

Quizplus · Accepted Answer

The Answer of Use the sum-to-product formulas to rewrite the sum or difference as a product. ​
Cos 3θ + cos 8θ
​
A)​ $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
B)​ $2 \cos \frac { 11 \theta } { 2 } \sin - \frac { 5 \theta } { 2 }$
C)​ $2 \sin \frac { 11 \theta } { 2 } \sin \frac { 5 \theta } { 2 }$
D)​ $\cos - \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
E) $2 \cos \frac { 11 \theta } { 2 } \cos - \frac { 5 \theta } { 2 }$

Use the Sum-To-Product Formulas to Rewrite the Sum or Difference cos⁡11θ2cos⁡5θ2\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }cos211θ​cos25θ​

Use the Sum-To-Product Formulas to Rewrite the Sum or Difference $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$