Integral of Cosec(x)/Sec(x) (i.e. Use of trignometric identities)

∫  Cosec (x)/Sec (x) dx∫  [1/Sin (x)]/ [1/Cos (x)] dx∫  [1/Sin (x)] * [Cos (x)] dx∫  Cot (x)= ln [Sin (x)] + c