Find the expression as the cosine of an angle.
$\cos \frac { \pi } { 5 } \cos \frac { \pi } { 3 } - \sin \frac { \pi } { 5 } \sin \frac { \pi } { 3 }$
A) $\sin \frac { 15 \pi } { 8 }$
B) $\cos \frac { 15 \pi } { 8 }$
C) $\cos \frac { 8 \pi } { 15 }$
D) $\cos \frac { \pi } { 15 }$
E) $\sin \frac { 8 \pi } { 15 }$

Question

Find the expression as the cosine of an angle.  
  $\cos \frac { \pi } { 5 } \cos \frac { \pi } { 3 } - \sin \frac { \pi } { 5 } \sin \frac { \pi } { 3 }$ 
A) $\sin \frac { 15 \pi } { 8 }$
B) $\cos \frac { 15 \pi } { 8 }$
C) $\cos \frac { 8 \pi } { 15 }$
D) $\cos \frac { \pi } { 15 }$
E) $\sin \frac { 8 \pi } { 15 }$

Quizplus · Accepted Answer

The Answer of Find the expression as the cosine of an angle.  
  $\cos \frac { \pi } { 5 } \cos \frac { \pi } { 3 } - \sin \frac { \pi } { 5 } \sin \frac { \pi } { 3 }$ 
A) $\sin \frac { 15 \pi } { 8 }$
B) $\cos \frac { 15 \pi } { 8 }$
C) $\cos \frac { 8 \pi } { 15 }$
D) $\cos \frac { \pi } { 15 }$
E) $\sin \frac { 8 \pi } { 15 }$

Find the Expression as the Cosine of an Angle cos⁡π5cos⁡π3−sin⁡π5sin⁡π3\cos \frac { \pi } { 5 } \cos \frac { \pi } { 3 } - \sin \frac { \pi } { 5 } \sin \frac { \pi } { 3 }cos5π​cos3π​−sin5π​sin3π​

Find the Expression as the Cosine of an Angle $\cos \frac { \pi } { 5 } \cos \frac { \pi } { 3 } - \sin \frac { \pi } { 5 } \sin \frac { \pi } { 3 }$