Question

Solve using periodic properties:

Sin^-1(sin(5π/8))

cos (16π/3)

Assuming you don't have a calculator to check your work, I don't understand how to find the corresponding angle on the periodic circle. I really need a detailed explanation. I understand the math so I don't need someone showing me how to subtract 5π-2π =3π, but more so how you would know how to subtract 5-2 as opposed to 5π-4π to get π/8? I've seen people solve many questions like these different ways, but each way doesn't work for every kind of problem. Please no sloppy handwriting! I don't understand this at all!

Answer 1

If you still have some problem you can ask in the comments