y = 1 + cos x / - sin x dy/dx=.......

jawab

y = (1 + cos x) / (- sin x)

u = 1 + cosx 
u' = - sin x

v = - sin x
v' = - cos x

y = u/v
y' = (u' v + uv') / (v²)

y' = {(-sin x)(-sin x) + (1+cos x)(-cos x)}/ (- sin x)²
y' = {sin² x - cos x  - cos² x} / (sin² x)

y' = sin² x/ sin²x  - cos x / sin² x - cos²x /.sin² x
y' = 1 - cos x . csc x -  cot² x