(EsPCEx - 2014)O valor de :
(EsPCEx - 2014)
O valor de \(\left( cos \left( 165^{\circ} \right ) + sen \left( 155^{\circ} \right ) + cos\left( 145^{\circ} \right ) - sen \left( 25^{\circ} \right ) + cos \left( 35^{\circ} \right ) + cos \left( 15^{\circ} \right )\right )\) é:
A
\(\sqrt{2}\)
B
-1
C
0
D
1
E
\(\frac{1}{2}\)
