Express the sum or difference as a product of sines and/or cosines.
-$\cos ( 10 \theta ) - \cos ( 4 \theta )$
A) $2 \cos ( 3 \theta )$
B) $2 \cos ( 7 \theta ) \cos ( 3 \theta )$
C) $- 2 \sin ( 7 \theta ) \sin ( 3 \theta )$
D) $- 2 \cos ( 7 \theta ) \sin ( 3 \theta )$

Question

Quizplus · Accepted Answer

The Answer of Express the sum or difference as a product of sines and/or cosines.
-$\cos ( 10 \theta ) - \cos ( 4 \theta )$
A) $2 \cos ( 3 \theta )$
B) $2 \cos ( 7 \theta ) \cos ( 3 \theta )$
C) $- 2 \sin ( 7 \theta ) \sin ( 3 \theta )$
D) $- 2 \cos ( 7 \theta ) \sin ( 3 \theta )$

Express the Sum or Difference as a Product of Sines cos⁡(10θ)−cos⁡(4θ)\cos ( 10 \theta ) - \cos ( 4 \theta )cos(10θ)−cos(4θ)

Express the Sum or Difference as a Product of Sines $\cos ( 10 \theta ) - \cos ( 4 \theta )$