Which Radians to Use in Calculating Phase Constants?

[lostie100]

I just have a simple question as to which radians to use in calculating phase constants in oscillations.
For example in sin(theta) = 1/2, do I use the (pi)/6 or 5(pi)/6?

The exact question has a diagram and is difficult to explain, but I just want a general explanation.

Thank you!

 

[Redbelly98]

It's a little hard to answer this without more information. If you're just trying to solve the equation,

\sin \theta = 1/2

then there are more than one solution.

But you did say the problem deals with oscillations and phase constants. Can you use the information that:
1) at pi/6, the oscillation's displacement is increasing
2) whereas at 5 pi/6, the displacement is decreasing
to somehow decide on one value or the other? The answer would depend on details of the problem you are trying to solve.