Find the principal value of each of the following:
= 
= 
For any x 
[–1,1], 
represents an angle in [0, 
] whose cosine is x.
Principal value of 
is 
.
4
Find the principal value of each of the following:
=
=
For any x [–1,1], represents an angle in [0, ] whose cosine is x.
Principal value of is .