y = sin (x a) ∘ where a is called the phase angle. This is when the graph of the function has been shifted to the left or right by a degrees.

In this animation, we see what the “polygonal sine” looks like for [the square, the hexagon, the triangle and the heart. The polygon is such that the inscribed circle has radius 1.

From the graph of the function, we can see that we should be expecting 2 solutions: 1 solution between 0 ∘ and 90 ∘ and the other between 90 ∘ and 180 ∘. sin x ∘ = 3 4 ...