You can put this solution on YOUR website! 1-((sin^2x)/(1-cosx))=(1/2)
1-(1-cos^2x)/(1-cos x)=(1/2)
1- [(1+cos x)(1- cos x)/(1-cos x)]=(1/2)
1-(1+cos x)=(1/2)
1-1-cos x=(1/2)
cos x=(-1/2)
on the 0 to 2 pi interval, that occurs at 2 pi/3 and 4 pi/3.
Where the cosine is -0.5, the sine is +or- sqrt(3)/2
[1-(3/4)/(3/2)]=1-(1/2)=(1/2)