Find the principal values of each of the following:
cot–1(–√3)
Let cot–1(–√3) = y
⇒ cot y = –√3
= – cot
= √3
= cot
= cot
The range of principal value of cot–1is (0, π)
and cot
= –√3
∴ The principal value of cot–1(–√3) is 
1
Find the principal values of each of the following:
cot–1(–√3)
Let cot–1(–√3) = y
⇒ cot y = –√3
= – cot = √3
= cot
= cot
The range of principal value of cot–1is (0, π)
and cot = –√3
∴ The principal value of cot–1(–√3) is