Question

How do you find the exact values of sin 195° using the half angle formula?

Answer 1

`(1-sqrt3)/(2sqrt2)`

Explanation:

Sin 195= sin(180+15)= -sin 15= `-sqrt[1/2 (1-cos30)]= -sqrt[1/2(1-sqrt3 /2)`

=-`sqrt((2-sqrt3)/4)`

=-`sqrt((4-2sqrt3)/8)`

= - `(sqrt3 -1)/(2sqrt2)`

= `(1-sqrt3)/(2sqrt2)`