Evaluate each of the following:
The value of cot
is 1.
∴ The question becomes cot–1(1).
Let cot–1(1) = y
⇒ cot y = 1
= cot
= 1
The range of principal value of cot–1is (0, π)
and cot
= 1
∴ The value of cot–1(cot
) is 
.
6
Evaluate each of the following:
The value of cot is 1.
∴ The question becomes cot–1(1).
Let cot–1(1) = y
⇒ cot y = 1
= cot = 1
The range of principal value of cot–1is (0, π)
and cot = 1
∴ The value of cot–1(cot) is .