Find the values of :
(i) `tan (-30^(@))`
(ii) `sin 120^(@)`
(iii) `sin 135^(@)`
(iv) `cos 150^(@)`
(v) `sin 270^(@)`
(vi) `cos 270^(@)`

Answer

(i) `-(1)/(sqrt3)`
(ii) `(sqrt3)/(2)`
(iii) `(1)/(sqrt2)`
(iv) `- (sqrt3)/(2)`
(v) `-1`
(vi) 0

Explanation

(i) `tan (-30^(@))= tan 30^(@)= -(1)/(sqrt3)`
(ii) `sin (120^(@)) = sin (180^(@) - 60^(@))`
`= sin 60^(@) = (sqrt3)/(2)`
(iii) `sin (135^(@)) = sin (90^(@) + 45^(@)) = cos 45^(@) = (1)/(sqrt2) `
(iv) `cos (150^(@)) = cos (180^(@) - 30^(@)) = - cos(30^(@)) = - (sqrt3)/(2)`
(v) `sin (270^(@)) = (-1)` (from graph )