Find the principal value of each of the following :
[Formula: cos(2π – x) = cos (x), as cos has a positive vaule in the fourth quadrant. ]
= 
[Formula: cos-1(cos x) = x
= 
1
Find the principal value of each of the following :
[Formula: cos(2π – x) = cos (x), as cos has a positive vaule in the fourth quadrant. ]
= [Formula: cos-1(cos x) = x
=