Category
Trigonometry
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.
Latest problems
37 problems
Tangents and Cotangents in Balance
917
2
Trig Value from a Quadrant
917
1
Where Sine and Cosine Cancel
917
1
A familiar right triangle
833
15
Sum of a bounded sine expression
833
2
A Tangent Beyond Full Turns
750
2
A telescoping tangent product
833
3
An Exact Value at Seventy-Five Degrees
833
2
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