{"id":1221,"date":"2015-08-13T22:49:14","date_gmt":"2015-08-13T13:49:14","guid":{"rendered":"http:\/\/www.roundown.net\/nyushi\/?p=1221"},"modified":"2021-03-09T15:58:49","modified_gmt":"2021-03-09T06:58:49","slug":"tkr201501","status":"publish","type":"post","link":"https:\/\/www.roundown.net\/nyushi\/tkr201501\/","title":{"rendered":"\u6771\u5927\u7406\u7cfb2015\uff1a\u7b2c1\u554f"},"content":{"rendered":"<hr \/>\n<p>\u6b63\u306e\u5b9f\u6570 \\(a\\) \u306b\u5bfe\u3057\u3066, \u5ea7\u6a19\u5e73\u9762\u4e0a\u3067\u6b21\u306e\u653e\u7269\u7dda\u3092\u8003\u3048\u308b. \r\n\\[\r\nC \\ : \\ y = ax^2 +\\dfrac{1 -4a^2}{4a}\r\n\\]\r\n\\(a\\) \u304c\u6b63\u306e\u5b9f\u6570\u5168\u4f53\u3092\u52d5\u304f\u3068\u304d, \\(C\\) \u306e\u901a\u904e\u3059\u308b\u9818\u57df\u3092\u56f3\u793a\u305b\u3088.<\/p>\r\n<hr>\r\n<!--more-->\r\n<h4>\u3010 \u89e3 \u7b54 \u3011<\/h4>\r\n<p>\\(C\\) \u306e\u5f0f\u3092\u5909\u5f62\u3059\u308b\u3068\r\n\\[\\begin{align}\r\n4ay = 4a^2 x^2 +1 & -4a^2 \\\\\r\n4 ( x^2 -1 ) a^2 -4y a +1 & = 0 \\quad ... [1]\r\n\\end{align}\\]\r\n\u3053\u308c\u3092 \\(a\\) \u306e\u65b9\u7a0b\u5f0f\u3068\u307f\u3066, \\(a \\gt 0\\) ... [2] \u306a\u308b\u89e3\u3092\u3082\u3064\u305f\u3081\u306e\u6761\u4ef6\u3092\u6c42\u3081\u308c\u3070\u3088\u3044.<br \/>\r\n[1] \u306e\u5de6\u8fba\u3092 \\(f(a)\\) \u3068\u304a\u304f.<\/p>\r\n<ol>\r\n<li><p><strong>1*<\/strong>\u3000\\(x^2 -1 = 0\\) \u3059\u306a\u308f\u3061 \\(x = \\pm 1\\) \u306e\u3068\u304d<br \/>\r\n[1] \u3092\u3068\u304f\u3068\r\n\\[\\begin{align}\r\nf(a) = -4ya +1 & = 0 \\\\\r\n\\text{\u2234} \\quad a & = \\dfrac{1}{4y} \\quad ( y \\neq 0 )\r\n\\end{align}\\]\r\n\u3053\u308c\u304c, [2] \u3092\u307f\u305f\u3059\u306e\u3067\r\n\\[\\begin{align}\r\n\\dfrac{1}{4y} & \\gt 0 \\\\\r\n\\text{\u2234} \\quad y & \\gt 0 \\quad ... [3]\r\n\\end{align}\\]<\/li>\r\n<li><p><strong>2*<\/strong>\u3000\\(x^2 -1 \\lt 0\\) \u3059\u306a\u308f\u3061 \\(-1 \\lt x \\lt 1\\) \u306e\u3068\u304d<br \/>\r\n\\(f(0) = 1 \\gt 0\\) \u306a\u306e\u3067, [1] \u306f\u304b\u306a\u3089\u305a\u6b63\u306e\u89e3\u3092\u3082\u3064.<\/p><\/li>\r\n<li><p><strong>3*<\/strong>\u3000\\(x^2 -1 \\gt 0\\) \u3059\u306a\u308f\u3061 \\(x \\lt -1 , 1 \\lt x\\) \u306e\u3068\u304d<br \/>\r\n\u6c42\u3081\u308b\u6761\u4ef6\u306f\r\n<ul>\r\n<li>[1] \u306e\u5224\u5225\u5f0f \\(D\\) \u306b\u3064\u3044\u3066\uff1a\r\n\\[\\begin{align}\r\n\\dfrac{D}{4} = (2y)^2 -4 ( x^2 -1 ) & \\geqq 0 \\\\\r\n\\text{\u2234} \\quad x^2 -y^2 & \\geqq 1 \\quad ... [4]\r\n\\end{align}\\]<\/li>\r\n<li>\\(2\\) \u6b21\u95a2\u6570 \\(f(a)\\) \u306e\u8ef8\u306e\u4f4d\u7f6e\u306b\u3064\u3044\u3066\uff1a\r\n\\[\\begin{align}\r\n\\dfrac{x^2 -1}{2y} & \\gt 0 \\\\\r\n\\text{\u2234} \\quad y & \\gt 0 \\quad ... [5]\r\n\\end{align}\\]<\/li>\r\n<\/ul>\r\n\u3086\u3048\u306b, [4] \u304b\u3064 [5] \u3067\u3042\u308b.<\/p><\/li>\r\n<\/ol>\r\n<p><strong>1*<\/strong>\uff5e<strong>3*<\/strong>\u3088\u308a, \u6c42\u3081\u308b\u9818\u57df\u306f, \u4e0b\u56f3\u659c\u7dda\u90e8\uff08\u5b9f\u7dda\u5883\u754c\u542b\u307f, \u70b9\u7dda\u5883\u754c\u3068\u25cb\u306f\u542b\u307e\u306a\u3044\uff09. <\/p>\r\n<img decoding=\"async\" src=\"\/\/www.roundown.net\/nyushi\/wp-content\/uploads\/tkr20150101.svg\" alt=\"tkr20150101\" class=\"aligncenter size-full wp-image-1222\" \/>\r\n","protected":false},"excerpt":{"rendered":"\u6b63\u306e\u5b9f\u6570 \\(a\\) \u306b\u5bfe\u3057\u3066, \u5ea7\u6a19\u5e73\u9762\u4e0a\u3067\u6b21\u306e\u653e\u7269\u7dda\u3092\u8003\u3048\u308b. \\[ C \\ : \\ y = ax^2 +\\dfrac{1 -4a^2}{4a} \\] \\(a\\) \u304c\u6b63\u306e\u5b9f\u6570\u5168\u4f53\u3092\u52d5\u304f\u3068\u304d, \\(C\\) \u306e\u901a\u904e\u3059\u308b\u9818 &hellip; <a href=\"https:\/\/www.roundown.net\/nyushi\/tkr201501\/\">\u7d9a\u304d\u3092\u8aad\u3080 <span class=\"meta-nav\">&rarr;<\/span><\/a>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[125],"tags":[139,137],"class_list":["post-1221","post","type-post","status-publish","format-standard","hentry","category-tokyo_r_2015","tag-tokyo_r","tag-137"],"_links":{"self":[{"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/posts\/1221","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/comments?post=1221"}],"version-history":[{"count":0,"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/posts\/1221\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/media?parent=1221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/categories?post=1221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.roundown.net\/nyushi\/wp-json\/wp\/v2\/tags?post=1221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}