Mark the tick against the correct answer in the following:
The principal value of cot-1 (-1) is
To Find: The Principle value of 
Let the principle value be given by x
Now, let x =
cot x =-1
cot x= - cot(
) (
)=
)
cot x=cot(
) (
))
x = 
1
Mark the tick against the correct answer in the following:
The principal value of cot-1 (-1) is
To Find: The Principle value of
Let the principle value be given by x
Now, let x =
cot x =-1
cot x= - cot() ()=)
cot x=cot() ())
x =