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
1