(a) Find the value of followings :
(i) `sin 150^(@)` , (ii) ` cos 135^(@)` , (iii) ` cos (-30^(@))`, (iv) ` tan 225^(@)` .
(b) If ` cos theta =(4)/(5) `. Find the value of ` sin theta` and ` tan theta` .
(c) Find the value of ` sin ^(-1)(1)` .

Explanation

(a) (i) `(1)/(2) `, (ii) `-(1)/(sqrt(2))` , (iii) ` (sqrt(3))/(2)` , (iv) 1
(b) `sin theta=(3)/(5)`
` tan theta =(3)/(4)`
(c) ` (pi)/(2)`