Answer:
-sqrt(3)/2
Explanation:
Use double angle identity for sin(2x)
sin(2x)=2sin(x)cos(x)
We are given sin(x)=-1/2 so we already have so far that:
sin(2x)=2(-1/2)cos(x)
sin(2x)=-1*cos(x)
We just need to find cos(x).
x is in the fourth quadrant so cosine will be positive there
knowing the unit circle we should know that if sin(x)=-1/2 then cos(x)=sqrt(3)/2 while in 4th quadrant.
So the answer is sin(2x)=-1*sqrt(3)/2=-sqrt(3)/2