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]

∴

1