simplify sin (π+x) - sin (π-x)
a. -2cos x
b. -2 sin x
c. 2 cos x
d. 2 sin x
sin (pi + x) - sin (pi - x)
[ sin pi * cos x + sin x * cos pi ] - [ sin pi * cos x - sin x * cos pi ] =
2sin x * cos pi =
2sinx * -1
-2sin x
Because sin(π+x)=−sin(π−x)
sin(π+x)−sin(π−x)=−sin(π−x)−sin(π−x)=−2⋅sin(π−x)|sin(π−x)=sin(x)=−2⋅sin(x)
+36 
