The value of cot−11−sinx+1+sinx1−sinx−1+sinx is
π-x
π-x2
π-x3
None of these
cot−1cos12x−sin12x+cos12x+sin12xcos12x−sin12x−cos12x+sin12x=cot−1−cot12x=cot−1cotπ−12x=π−12x