Question

How do you use half angle formula to find `sin ((11pi)/12)`?

Answer 1

On the trig unit circle, `sin (11pi)/12 = sin (pi/12)`

`2sin^2 (pi/12) = 1 - cos (pi/6)`= `1 - (sqr3)/2 = 0.134`

`sin^2 (pi/12) = 0.067 -> sin (pi/12) = sin ((11pi)/12) = 0.26.`