Answers

2014-05-22T17:13:47+05:30
 Lhs=cot^-1[(cosx+sinx)/(cosx-sinx)]
now for inverse trio function
eg there is formula
sin^-1(sinx)=x
similarly
cot^-1(cot (pi/4-x))=pi/4-x
now
cot(pi/4-x)=(cosx+sinx)/(cosx-sinx)
so
Lhs=pi/4-x
LHS=RHS
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