Find the principal values of each of the following:
Let cot–1(
) = y
⇒ cot y = 
= – cot
= cot
= cot
The range of principal value of cot–1is (0, π)
and cot
∴ The principal value of cot–1(
) is 
1
Find the principal values of each of the following:
Let cot–1() = y
⇒ cot y =
= – cot
= cot
= cot
The range of principal value of cot–1is (0, π)
and cot
∴ The principal value of cot–1() is