Question

Need help with trig question

Answer 1

when I take the \[\sin^{-1} (-1/2) = - (1/6)\Pi \] So where does the seven come from?

Answer 2

I get that adding Pi would produce it but why?

Answer 3

Or, actually, just adding pi wouldn't produce it as - Pi/6 plus Pi equals 5Pi/6

Answer 4

Aaaahhhh sin(Pi - x) = sin x
I.e. sin(Pi - - Pi/6) = Sin (7Pi/6)