Find the principal value of :
(i) 
(ii) 
(iii) 
(iv) tan-1 (1)
(v) 
(vi) 
(vii)![]()
NOTE:
Trigonometric Table

(i) Let ![]()
⇒
[ We know which value of x when placed in sin gives us this answer ]
∴ ![]()
(ii) Let ![]()
⇒
[We know which value of x when put in this expression will give us this result]
⇒ ![]()
(iii) Let ![]()
⇒
[We know which value of x when put in this expression will give us this result]
∴ ![]()
(iv) Let ![]()
⇒
[We know which value of x when put in this expression will give us this result]
∴ ![]()
(v) Let ![]()
⇒
[We know which value of x when put in this expression will give us this result]
∴ ![]()
(vi) Let ![]()
⇒
[We know which value of x when put in this expression will give us this result]
∴ ![]()
(vii) Let ![]()
⇒ ![]()
[We know which value of x when put in this expression will give us this result]
∴ ![]()