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Function: require_once

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[잡담] [KAIST 과학영재교육연구원] k7. 거울 속 빛의 여행 문제 소문제 1번 도전
디듀우 2019.07.22 06:11 조회 412
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빛이 반사될 때마다 입사각과 반사각이 같으므로 계속 같은 방향으로 반사돼 돌아오면 정다각형의 대각선 경로가 됩니다. 정다각형의 한 각의 크기는 변이 n개일 때 180(n-2)이고 각 꼭짓점을 향하는 대각선 사이 각은 길이가 같은 현에 대한 원주각이므로 모두 크기가 같아 하나당 180(n-2)/n입니다. 이것의 정수배의 절반이므로 입사각 a는 임의의 자연수 n,m에 대해 180m(n-2)/2n꼴의 수여야 합니다.

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