MathDB

3

Part of 1957 Czech and Slovak Olympiad III A

Problems(1)

Integer values of cotangent function

Source: Czech and Slovak Olympiad 1957, National Round, Problem 3

4/10/2020
Find all real numbers α\alpha such that both values cot⁡(α)\cot(\alpha) and cot⁡(2α)\cot(2\alpha) are integers.
number theorytrigonometric functionnational olympiadfunction