{"id":1933,"date":"2019-03-23T14:00:25","date_gmt":"2019-03-23T05:00:25","guid":{"rendered":"http:\/\/math.co.jp\/blog\/?p=1933"},"modified":"2019-06-22T10:41:29","modified_gmt":"2019-06-22T01:41:29","slug":"%e6%95%b0%e5%ad%a6%e3%81%ae%e5%ad%a6%e7%bf%92%e3%81%ae%e4%bb%95%e6%96%b9%e6%a6%82%e8%ab%96%e7%b7%a8","status":"publish","type":"post","link":"https:\/\/math.co.jp\/blog\/?p=1933","title":{"rendered":"\u6570\u5b66\u306e\u5b66\u7fd2\u306e\u4ed5\u65b9(\u6982\u8ad6\u7de8)"},"content":{"rendered":"\n

\u6570\u5b66\u306e\u5b66\u7fd2\u306b\u304a\u3044\u3066\u91cd\u8981\u306a\u3053\u3068\u306f\u3044\u304f\u3064\u3082\u3042\u308a\u307e\u3059\u304c, \u5b66\u7fd2\u521d\u671f\u306b\u304a\u3044\u3066\u306f\u6b21\u306e 3 \u3064\u306e\u81ea\u899a\u304c\u5927\u5207\u3067\u3059\u3002\u4eca\u56de\u306f, \u3053\u306e 3 \u3064\u306b\u3064\u3044\u3066\u6982\u8981\u3092\u8aac\u660e\u3057\u307e\u3059\u3002\u3069\u308c\u3082\u300c\u3042\u305f\u308a\u307e\u3048\u300d\u3068\u601d\u308f\u308c\u304c\u3061\u306a\u306e\u3067\u3059\u304c\u30bf\u30a4\u30c8\u30eb\u306b\u7d9a\u304f\u4f8b\u3092\u4e00\u5ea6\u3088\u304f\u8aad\u3093\u3067\u307f\u3066\u304f\u3060\u3055\u3044\u3002 \n

    \n
  1. \u3000\u308f\u304b\u3089\u306a\u304f\u306a\u3063\u305f\u3089\u308f\u304b\u308b\u3068\u3053\u308d\u307e\u3067\u623b\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3053\u3068<\/b><\/br>\n\u6570\u5b66\u306e\u5b66\u7fd2\u306e\u3059\u3079\u3066\u3068\u307e\u3067\u306f\u8a00\u3044\u307e\u305b\u3093\u304c, \u6570\u5b66\u306e\u5b66\u7fd2\u3067\u308f\u304b\u3089\u306a\u3044\u8a71\u304c\u51fa\u3066\u304d\u305f\u3068\u304d\u306f, \u305d\u308c\u304c\u51fa\u3066\u304d\u305f\u7d4c\u8def\u3092\u305f\u3069\u308a\u5143\u306b\u623b\u308d\u3046\u3068\u3059\u308b\u300c\u59ff\u52e2\u300d\u304c\u5927\u5207\u3067\u3059\u3002\u306a\u304a, \u5b9f\u969b\u306b\u5143\u306b\u623b\u3063\u3066\u793a\u305b\u305f\u304b\u3069\u3046\u304b\u306f\u5927\u5207\u3067\u3059\u304c\u305d\u306e\u6b21\u306e\u3053\u3068\u3067\u3059\u3002<\/br>\n \u3000\u4f8b\u3048\u3070, \u4e09\u89d2\u95a2\u6570\u306e 2 \u500d\u89d2\u306e\u516c\u5f0f \n $$\\sin 2\\theta =2\\sin \\theta\\cos\\theta$$\n $$\\cos 2\\theta =\\cos^{2}\\theta -\\sin^{2}\\theta$$\n\u3092\u5fd8\u308c\u305f\u3068\u3057\u307e\u3059\u3002\u3053\u306e 2 \u500d\u89d2\u306e\u516c\u5f0f\u3092\u4e38\u6697\u8a18\u3059\u308b\u304b\u3069\u3046\u304b\u304c\u3053\u3053\u3067\u306e\u8ad6\u70b9\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u3053\u306e 2 \u500d\u89d2\u306e\u516c\u5f0f\u304c\u3059\u3050\u306b\u51fa\u3066\u3053\u306a\u3044\u3068\u304d\u306b, \u305d\u308c\u3088\u308a\u3082\u57fa\u672c\u3067\u3042\u308b\u300c\u4e09\u89d2\u95a2\u6570\u306e\u52a0\u6cd5\u5b9a\u7406\u300d\u306b\u623b\u3063\u3066\u305d\u3053\u304b\u3089 2 \u500d\u89d2\u306e\u516c\u5f0f\u3092\u5c0e\u304d\u51fa\u305d\u3046\u3068\u3057\u3088\u3046\u3068\u3059\u308b\u304b\u3069\u3046\u304b\u304c\u5927\u5207\u3067\u3059\u3002<\/br>\n \u3000\u3053\u306e\u4ed6\u306b\u3082, \u4e09\u89d2\u95a2\u6570\u306e\u548c\u7a4d\u516c\u5f0f\u306a\u3069\u3082\u5fd8\u308c\u305f\u3068\u304d\u306b, \u3053\u308c\u304c\u5c0e\u304d\u51fa\u3055\u308c\u305f\u7d4c\u7def\u3092\u8003\u3048\u3066\u9061\u308d\u3046\u3068\u3059\u308b\u59ff\u52e2\u304c\u5927\u5207\u306a\u306e\u3067\u3059\u3002 <\/br><\/br><\/li>\n
  2. \u3000\u521d\u3081\u3066\u898b\u308b\u3082\u306e\u306b\u3064\u3044\u3066\u306f, \u305d\u306e\u5b9a\u7fa9\u306b\u53b3\u683c\u306b\u5f93\u3046\u3053\u3068<\/b><\/br>\n\u3000\u300c\u3053\u308c\u3069\u3046\u306a\u306e\u3060\u308d\u3046?\u300d\u3068\u601d\u3063\u305f\u3068\u304d\u306b\u5b9a\u7fa9\u306b\u623b\u308a, \u305d\u306e\u5b9a\u7fa9\u306b\u53b3\u683c\u306b\u5f93\u3044\u5224\u65ad\u3059\u308b\u3053\u3068\u304c\u5927\u5207\u3067\u3059\u3002\u305d\u308c\u306f, \u5404\u81ea\u306e\u611f\u899a\u3067\u5224\u65ad\u3059\u308b\u3053\u3068\u306e\u53cd\u5bfe\u306e\u3053\u3068\u3067\u3059\u3002\u7279\u306b, \u300c\u898b\u305f\u3053\u3068\u304c\u306a\u3044\u300d\u300c\u805e\u3044\u305f\u3053\u3068\u304c\u306a\u3044\u300d\u300c\u3084\u3063\u305f\u3053\u3068\u304c\u306a\u3044\u300d\u3068\u3044\u3046\u3053\u3068\u3092\u7406\u7531\u306b\u5224\u65ad\u3059\u308b\u3053\u3068\u306f\u6570\u5b66\u7684\u306b\u306f\u5168\u304f\u306e\u7121\u610f\u5473\u3067\u3059\u3002<\/br>\n \u3000\u3067\u306f, \u4e00\u3064\u306e\u4f8b\u3092\u6319\u3052\u307e\u3057\u3087\u3046\u3002 \u6574\u6570 \\(a\\) \u304c\u6574\u6570 \\(b\\) \u306e\u7d04\u6570\u3067\u3042\u308b\u3053\u3068\u306e\u5b9a\u7fa9\u306f, <\/br><\/br>\n \u3000\u3000\u300c\\(ax=b\\) \u3092\u6e80\u305f\u3059\u6574\u6570 \\(x\\) \u304c\u5b58\u5728\u3059\u308b\u3053\u3068\u300d<\/br><\/br>\n \u3067\u3059\u3002\u4f8b\u3048\u3070, \u6574\u6570 3 \u304c\u306a\u305c\u6574\u6570 6 \u306e\u7d04\u6570\u3067\u3042\u308b\u304b\u3068\u3044\u3046\u3068, \\(3x=6\\) \u3092\u6e80\u305f\u3059\u6574\u6570 \\(x\\) (\u5b9f\u969b\u306b \\(x=2\\) ) \u304c\u5b58\u5728\u3059\u308b\u304b\u3089\u3067\u3059\u3002<\/br>\n \u3000\u3055\u3066, \u305d\u308c\u3067\u306f\u300c0 \u306e\u7d04\u6570\u300d\u306f\u4f55\u306a\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u305d\u306e\u3088\u3046\u306a\u5834\u5408\u3067\u3082\u72ec\u81ea\u306a\u5224\u65ad\u3092\u3059\u308b\u306e\u3067\u306f\u306a\u304f, \u300c\u5b9a\u7fa9\u300d\u901a\u308a\u306b\u8003\u3048\u307e\u3059\u3002\u5b9a\u7fa9\u306b\u5f93\u3046\u3068, <\/br><\/br>\n \u3000\u3000\u300c\\(ax=0\\) \u3092\u6e80\u305f\u3059\u6574\u6570 \\(x\\) \u304c\u5b58\u5728\u3059\u308b\u3088\u3046\u306a \\(a\\) \u306e\u3053\u3068\u300d<\/br><\/br>\n\u3067\u3059\u3002\u3057\u304b\u3057, \u3053\u306e\u5834\u5408, \u65b9\u7a0b\u5f0f \\(ax=0\\) \u306f \\(x=0\\) \u304c\u3064\u306d\u306b\u6e80\u305f\u3057\u307e\u3059\u3002\u3064\u307e\u308a, \\(a\\) \u304c\u3069\u306e\u3088\u3046\u306a\u6574\u6570\u3067\u3042\u3063\u3066\u3082 \\(ax=0\\) \u3092\u6e80\u305f\u3059\u6574\u6570 \\(x\\) \u306f\u5b58\u5728\u3059\u308b\u306e\u3067\u3059\u3002\u3057\u305f\u304c\u3063\u3066, 0 \u306e\u7d04\u6570\u306f\u3059\u3079\u3066\u306e\u6574\u6570\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/br>\n \u3000\u6b21\u306b\u300c\u4e92\u3044\u306b\u7d20\u300d\u306b\u3064\u3044\u3066\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u6574\u6570 \\(a\\) \u3068\u6574\u6570 \\(b\\) \u304c\u4e92\u3044\u306b\u7d20\u3067\u3042\u308b\u3068\u306f, \u300c\\(a\\) \u3068 \\(b\\) \u306e\u6700\u5927\u516c\u7d04\u6570\u304c 1 \u3067\u3042\u308b\u3053\u3068\u300d\u3067\u3059\u3002\u3082\u3061\u308d\u3093\u3053\u308c\u3068\u540c\u5024\u306a\u6761\u4ef6\u3092\u5b9a\u7fa9\u306b\u3059\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070 6 \u3068 35 \u306f\u4e92\u3044\u306b\u7d20\u3067\u3059\u3002\u3067\u306f, \u300c0 \u3068\u4e92\u3044\u306b\u7d20\u306b\u306a\u308b\u6574\u6570 \\(x\\)\u300d\u306f\u4f55\u3067\u3057\u3087\u3046\u304b? \u3053\u308c\u3082\u5b9a\u7fa9\u306b\u623b\u3063\u3066\u8003\u3048\u308c\u3070\u3088\u3044\u306e\u3067\u3059\u3002<\/br><\/br>\n \u3000\u30fb 0 \u306e\u7d04\u6570\u306f\u3059\u3079\u3066\u306e\u6574\u6570\u3067\u3042\u308b<\/br>\n \u3000\u30fb \u3057\u305f\u304c\u3063\u3066, \u300c0 \u3068 \\(a\\) \u306e\u6700\u5927\u516c\u7d04\u6570\u304c 1 \u300d\u3068\u306a\u308b \\(a\\) \u306f \\(a\\) \u306e\u7d04\u6570\u304c 1 \u3060\u3051\u3067\u3042\u308b<\/br><\/br>\n \u3068\u306a\u308a\u307e\u3059\u304b\u3089, \\(a=\\pm 1\\) \u304c 0 \u3068 1 \u304c\u4e92\u3044\u306b\u7d20\u306b\u306a\u308b\u6574\u6570\u3067\u3059\u3002 <\/br><\/br><\/li>\n
  3. \u3000\u8a00\u8449\u3092\u6b63\u78ba\u306b\u3068\u3089\u3048\u308b<\/b><\/br>\n \u3000\u3053\u308c\u3082\u5f53\u7136\u306e\u3053\u3068\u306b\u805e\u3053\u3048\u307e\u3059\u304c, \u5b9f\u969b\u306f\u305d\u3046\u306a\u3089\u306a\u3044\u3068\u304d\u304c\u591a\u304f\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070, <\/br><\/br>\n \u3000\u3000\u300c\u7121\u7406\u6570\u3068\u7121\u7406\u6570\u306e\u548c\u306f\u7121\u7406\u6570\u306b\u306a\u308b\u3068\u306f\u300e\u9650\u3089\u306a\u3044\u300f\u300d<\/br><\/br>\n \u3068\u3044\u3046\u8868\u73fe\u3067\u3059\u304c, \u3053\u308c\u304c<\/br><\/br>\n \u3000\u3000\u300c\u7121\u7406\u6570\u3068\u7121\u7406\u6570\u306e\u548c\u306f\u7121\u7406\u6570\u300e\u3067\u306f\u306a\u3044\u300f\u300d<\/br><\/br>\n\u306b\u5909\u3048\u3089\u308c\u3066\u7406\u89e3\u3055\u308c\u3066\u3057\u307e\u3046\u3053\u3068\u3082\u591a\u3005\u3042\u308a\u307e\u3059\u3002<\/br>\n \u30002 \u3064\u306e\u7121\u7406\u6570 \\(\\sqrt{2}\\), \\(\\sqrt{3}\\) \u3092\u52a0\u3048\u308b\u3068 \\(\\sqrt{2}+\\sqrt{3}\\) \u3067\u3059\u304c, \u3053\u308c\u306f\u7121\u7406\u6570\u3067\u3059\u3002\u3057\u304b\u3057, \\((1+\\sqrt{2})+(1-\\sqrt{2})=2\\) \u306e\u3088\u3046\u306b 2 \u3064\u306e\u7121\u7406\u6570 \\(1+\\sqrt{2}\\), \\(1-\\sqrt{2}\\) \u3092\u52a0\u3048\u305f\u3082\u306e\u306f\u7121\u7406\u6570\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u3057\u305f\u304c\u3063\u3066, \u300c\u7121\u7406\u6570\u306b\u7121\u7406\u6570\u3092\u52a0\u3048\u305f\u5834\u5408, \u7d50\u679c\u306f\u7121\u7406\u6570\u306b\u306a\u308b\u3053\u3068\u3082\u3042\u308b\u304c, \u305d\u308c\u3060\u3051\u3067\u306f\u306a\u304f\u6709\u7406\u6570\u306b\u306a\u308b\u30b1\u30fc\u30b9\u3082\u3042\u308b\u300d\u3068\u3044\u3046\u4e3b\u5f35\u306a\u306e\u3067\u300e\u9650\u3089\u306a\u3044\u300f\u3068\u3044\u3046\u8868\u73fe\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u304c, \u3053\u308c\u3092\u300e\u3067\u306f\u306a\u3044\u300f\u306b\u3059\u308b\u3068\u610f\u5473\u304c\u5909\u308f\u3063\u3066\u304d\u307e\u3059\u3002 <\/li>\n<\/ol>\n<\/p>\n\n\n\n

    <\/p>\n","protected":false},"excerpt":{"rendered":"

    \u6570\u5b66\u306e\u5b66\u7fd2\u306b\u304a\u3044\u3066\u91cd\u8981\u306a\u3053\u3068\u306f\u3044\u304f\u3064\u3082\u3042\u308a\u307e\u3059\u304c, \u5b66\u7fd2\u521d\u671f\u306b\u304a\u3044\u3066\u306f\u6b21\u306e 3 \u3064\u306e\u81ea\u899a\u304c\u5927\u5207\u3067\u3059\u3002\u4eca\u56de\u306f, \u3053\u306e 3 \u3064\u306b\u3064\u3044\u3066\u6982\u8981\u3092\u8aac\u660e\u3057\u307e\u3059\u3002\u3069\u308c\u3082\u300c\u3042\u305f\u308a\u307e\u3048\u300d\u3068\u601d\u308f\u308c\u304c\u3061\u306a\u306e\u3067\u3059\u304c\u30bf\u30a4\u30c8\u30eb\u306b\u7d9a\u304f\u4f8b\u3092\u4e00\u5ea6\u3088\u304f\u8aad\u3093 […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-1933","post","type-post","status-publish","format-standard","hentry","category-19"],"_links":{"self":[{"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1933"}],"version-history":[{"count":11,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1933\/revisions"}],"predecessor-version":[{"id":1944,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1933\/revisions\/1944"}],"wp:attachment":[{"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/math.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}