Use the sum-to-product formulas to rewrite the sum or difference as a product. $$\sin 9 \theta + \sin 7 \theta$$
A) $2 \sin 8 \theta \sin \theta$
B) $2 \cos 8 \theta \cos \theta$
C) $2 \sin 8 \theta \cos \theta$
D) $2 \cos 8 \theta \sin \theta$
E) $2 \sin 9 \theta \cos 7 \theta$

Question

Use the sum-to-product formulas to rewrite the sum or difference as a product.​ $$\sin 9 \theta + \sin 7 \theta$$ ​
A)​ $2 \sin 8 \theta \sin \theta$
B)​ $2 \cos 8 \theta \cos \theta$
C)​ $2 \sin 8 \theta \cos \theta$ ​
D)​ $2 \cos 8 \theta \sin \theta$
E)​ $2 \sin 9 \theta \cos 7 \theta$

Quizplus · Accepted Answer

The Answer is C

Use the Sum-To-Product Formulas to Rewrite the Sum or Difference sin⁡9θ+sin⁡7θ\sin 9 \theta + \sin 7 \thetasin9θ+sin7θ

Use the Sum-To-Product Formulas to Rewrite the Sum or Difference $\sin 9 \theta + \sin 7 \theta$