Help:Tau day theorems 2 hints

This page is part of the tau day exercises.

Specifically, it is a series of hints for proving Interface:Tau day theorems 2 and is aimed at people who have gone through the exercises, tried to figure out Tau day theorems 2, but have not gotten it and would like a hint.

The first one, sin (τ / 2), can be derived from sin τ by SineHalfAngle.

The second one, cos (- τ / 4), is the complementary angle to τ / 2.

The third one, cos (τ / 4), follows by CosineNegation.

The fourth one, cos (τ / 8), follows by the half angle formula.

The last one, sin (τ / 8), follows by complementary angles.