Find the principal value of each of the following :
3
Putting the value of 
and using the formula
cot-1(-x)= π-cot-1x
= 
Putting the value of 
= 
= 
= 
=
1
Find the principal value of each of the following :
3
Putting the value of and using the formula
cot-1(-x)= π-cot-1x
=
Putting the value of
=
=
=
=