Identities, transformations, and angles that refuse to simplify.
Trigonometry sits between algebra and geometry, and contest problems exploit both sides of it. Identities compress an ugly expression; the unit circle turns angle chasing into arithmetic.
You will find identity manipulation, equations over restricted domains, sums of trigonometric series, and problems where the trigonometric form is a disguise for something much simpler underneath.
Browse every Trigonometry problem →