Find the principal values of each of the following:
sec–1(–√2)
Let sec–1(–√2) = y
⇒ sec y = –√2
= – sec
= √2
= sec
= sec
The range of principal value of sec–1is [0, π]–{
}
and sec
= –√2
∴ The principal value of sec–1(–√2) is 
.
1
Find the principal values of each of the following:
sec–1(–√2)
Let sec–1(–√2) = y
⇒ sec y = –√2
= – sec = √2
= sec
= sec
The range of principal value of sec–1is [0, π]–{}
and sec = –√2
∴ The principal value of sec–1(–√2) is .