• 올인원 · 1117418 · 01/28 22:19 · MS 2021

    S = cos(56°)cos(2×56°) ... cos(2²³×56°)

    sin(56°)cos(56°)cos(2×56°) ... cos(2²³×56°)
    = 1/2sin(2×56°)cos(2×56°) ... cos(2²³×56°)
    ...
    = 1/2²⁴ × sin(2²⁴×56°) = sin(56°) × S
    --> S = sin(2²⁴×56°)/{2²⁴sin(56°)}

    a = 2, n = 45, φ(n) = 24
    --> 2²⁴ = 1 (mod 360),
    2²⁴ × 56 = 56 (mod 360)
    sin(2²⁷×7°) = sin(2³×7°), S = 1/2²⁴

  • bdfh · 1232233 · 01/28 22:20 · MS 2023

    완벽합니다!

  • bdfh · 1232233 · 01/28 22:22 · MS 2023
    회원에 의해 삭제된 댓글입니다.
  • 올인원 · 1117418 · 01/29 08:32 · MS 2021

    정정)
    2²⁴ = 1 (mod 45)
    2²⁷ = 2³ (mod 360)
    2²⁷ × 7 = 2³ × 7 (mod 360)