Find the value of,
tan−1(cos x−sin xcos x+sin x), for 0<x<π.
tan−1(cos x−sin xcos x+sin x)=tan−1(cos xcos x−sin xcos xcos xcos x+sin xcos x)
(inside the bracket divide numerator and denominator by cosx)
=tan−1(1−tan x1+tan x)=tan−1[tan(π4−x)][∵tan(π4−x)=tanπ4−tan x1+tanπ4.tan x=1−tan x1+tan x]=π4−x