F(x)= sinx/1-cosx maka f'(x)

u = sin x
u' = cos x

v = 1 - cos x
v' = sin x

f(x) = u/v = sin x/(1 - cos x)

f'(x) = (u'v - uv')/v²
f'(x) = (cos x (1 - cos x) - sin x . sin x)/(1 - cos x)²
f'(x) = (cos x - (cos² x + sin² x) ) / (1 - cos x)²
f'(x) = (cos x - 1) / (1 - cos x)²
f'(x) = - (1 - cos x) / (1 - cos x)(1 - cos x)
f'(x) = -1/(1 - cos x)
f'(x) = 1/(cos x - 1)