{"id":4761,"date":"2022-03-07T21:29:25","date_gmt":"2022-03-07T12:29:25","guid":{"rendered":"https:\/\/hatsudy.com\/jp\/?p=4761"},"modified":"2022-07-20T21:44:10","modified_gmt":"2022-07-20T12:44:10","slug":"quadratic4","status":"publish","type":"post","link":"https:\/\/hatsudy.com\/jp\/quadratic4.html","title":{"rendered":"\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3068\u95a2\u6570\u306e\u30b0\u30e9\u30d5\uff1a\u5224\u5225\u5f0f\u306b\u3088\u308b\u5b9f\u6570\u89e3\u306e\u500b\u6570"},"content":{"rendered":"\n<p>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3092\u89e3\u304f\u3068\u304d\u3001\u7b54\u3048\u304c\u6574\u6570\u3067\u51fa\u306a\u3044\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u5834\u5408\u3001\u89e3\u306e\u516c\u5f0f\u3092\u4f7f\u3044\u307e\u3059\u3002\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3059\u308c\u3070\u3001\u7b54\u3048\u306b\u5e73\u65b9\u6839\u304c\u542b\u307e\u308c\u3066\u3044\u3066\u3082\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u89e3\u306e\u516c\u5f0f\u3092\u899a\u3048\u3066\u3044\u308c\u3070\u3001\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u304c\u3044\u304f\u3064\u306e\u7b54\u3048\u3092\u3082\u3064\u306e\u304b\u5224\u65ad\u3059\u308b\u305f\u3081\u306e\u5f0f\u304c\u5224\u5225\u5f0f\u3067\u3059\u3002<\/p>\n<p>\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308c\u3070\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3060\u3051\u3067\u306a\u304f\u3001\u4e8c\u6b21\u95a2\u6570\u3067\u306e\u7b54\u3048\u306e\u6570\u3092\u5224\u65ad\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u305d\u306e\u4e8c\u6b21\u95a2\u6570\u304c\u3069\u306e\u3088\u3046\u306a\u30b0\u30e9\u30d5\u3092\u63cf\u304f\u306e\u304b\u5224\u65ad\u3067\u304d\u308b\u306e\u3067\u3059\u3002\u307e\u305f\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308c\u3070\u3001\u653e\u7269\u7dda\u3068\u76f4\u7dda\u304c\u4ea4\u70b9\u3092\u3082\u3064\u304b\u3069\u3046\u304b\u3092\u8abf\u3079\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u3069\u306e\u3088\u3046\u306b\u3057\u3066\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3057\u3001\u5b9f\u6570\u89e3\u306e\u500b\u6570\u3092\u5224\u65ad\u3059\u308b\u306e\u304b\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<h2>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u7b54\u3048\u3092\u89e3\u306e\u516c\u5f0f\u3067\u51fa\u3059<\/h2>\n<p>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u7b54\u3048\u3092\u51fa\u3059\u3068\u304d\u3001\u6700\u3082\u4e00\u822c\u7684\u306a\u65b9\u6cd5\u306f\u56e0\u6570\u5206\u89e3\u3067\u3059\u3002\u56e0\u6570\u5206\u89e3\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u3001\u6574\u6570\u306e\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u305f\u3060\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3092\u56e0\u6570\u5206\u89e3\u3067\u304d\u306a\u3044\u30b1\u30fc\u30b9\u306f\u3069\u3046\u3059\u308c\u3070\u3044\u3044\u3067\u3057\u3087\u3046\u304b\u3002\u305d\u306e\u5834\u5408\u3001\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3057\u307e\u3059\u3002\u4e2d\u5b66\u6821\u3067\u5e73\u65b9\u6839\u3084\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u89e3\u306e\u51fa\u3057\u65b9\u3092\u5b66\u3093\u3067\u3044\u308b\u5834\u5408\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u89e3\u306e\u516c\u5f0f\u3092\u3059\u3067\u306b\u7fd2\u3063\u3066\u3044\u307e\u3059\u3002\u4ee5\u4e0b\u304c\u89e3\u306e\u516c\u5f0f\u3067\u3059\u3002<\/p>\n<p>$$x={-b\\pm\\sqrt{b^2-4ac}\\over2a}$$<\/p>\n<p><span style=\"color: #0000ff;\">\u3053\u306e\u516c\u5f0f\u306f\u5fc5\u305a\u899a\u3048\u306a\u3051\u308c\u3070\u3044\u3051\u307e\u305b\u3093\u3002<\/span>\u899a\u3048\u3066\u3044\u306a\u3044\u5834\u5408\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u554f\u984c\u3092\u89e3\u3051\u306a\u3044\u304b\u3089\u3067\u3059\u3002\u89e3\u304d\u65b9\u3068\u3057\u3066\u306f\u3001\u6570\u5b57\u3092\u4ee3\u5165\u3059\u308b\u3060\u3051\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u7b54\u3048\u306f\u4f55\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n<ul>\n<li>\\(2x^2+3x-4=0\\)<\/li>\n<\/ul>\n<p>\\(ax^2+bx-c=0\\)\u3068\\(2x^2+3x-4=0\\)\u3092\u6bd4\u3079\u308b\u3068\u3001\\(a=2\\)\u3001\\(b=3\\)\u3001\\(c=-4\\)\u3067\u3059\u3002\u305d\u3053\u3067\u3001\u6570\u5b57\u3092\u89e3\u306e\u516c\u5f0f\u306b\u4ee3\u5165\u3057\u307e\u3057\u3087\u3046\u3002\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\\(x=\\displaystyle\\frac{-b\u00b1\\sqrt{b^2-4ac}}{2a}\\)<\/p>\n<p>\\(x=\\displaystyle\\frac{-3\u00b1\\sqrt{3^2-4\u00d72\u00d7(-4)}}{2\u00d72}\\)<\/p>\n<p>\\(x=\\displaystyle\\frac{-3\u00b1\\sqrt{9+32}}{4}\\)<\/p>\n<p>\\(x=\\displaystyle\\frac{-3\u00b1\\sqrt{41}}{4}\\)<\/p>\n<p>\u3053\u3046\u3057\u3066\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<h3>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u5b9f\u6570\u89e3\u306e\u500b\u6570\uff1a\u5224\u5225\u5f0f<\/h3>\n<p>\u306a\u304a\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u89e3\u306e\u516c\u5f0f\u3092\u899a\u3048\u3066\u3044\u308b\u5834\u5408\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u304c\u3044\u304f\u3064\u7b54\u3048\u3092\u3082\u3064\u306e\u304b\u7406\u89e3\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u3092<span style=\"color: #ff0000;\">\u5224\u5225\u5f0f\uff08\\(D\\)\uff09<\/span>\u3068\u547c\u3073\u307e\u3059\u3002\u4ee5\u4e0b\u304c\u5224\u5225\u5f0f\u3067\u3059\u3002<\/p>\n<ul>\n<li>\\(D=b^2-4ac\\)<\/li>\n<\/ul>\n<p>\u5224\u5225\u5f0f\u3092\u899a\u3048\u308b\u5fc5\u8981\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u89e3\u306e\u516c\u5f0f\u3092\u78ba\u8a8d\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u90e8\u5206\u304c\u5224\u5225\u5f0f\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh2.jpg\" alt=\"\" width=\"463\" height=\"145\" class=\"aligncenter size-full wp-image-4764\" \/><\/p>\n<p>\u5224\u5225\u5f0f\\(D\\)\u3068\u3044\u3046\u306e\u306f\u3001\u89e3\u306e\u516c\u5f0f\u306e\u4e2d\u3067\u30eb\u30fc\u30c8\u5185\u306b\u3042\u308b\u5f0f\u3092\u6307\u3057\u307e\u3059\u3002\u305d\u308c\u3067\u306f\u3001\u5224\u5225\u5f0f\\(D\\)\u3092\u5b66\u3076\u3053\u3068\u304c\u306a\u305c\u91cd\u8981\u306a\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u305d\u308c\u306f\u3001<span style=\"color: #0000ff;\">\u5224\u5225\u5f0f\u3092\u78ba\u8a8d\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u304c\u3082\u3064\u7b54\u3048\u306e\u6570\u3092\u77e5\u308b\u3053\u3068\u304c\u3067\u304d\u308b<\/span>\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u5224\u5225\u5f0f\u306e\u7b54\u3048\u304c\u30d7\u30e9\u30b9\u306a\u306e\u304b\u30de\u30a4\u30ca\u30b9\u306a\u306e\u304b\u306b\u3088\u3063\u3066\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5b9f\u6570\u89e3\u306e\u500b\u6570\u304c\u5909\u308f\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li>\u5224\u5225\u5f0f\\(D&gt;0\\)\uff1a\u7570\u306a\u308b2\u3064\u306e\u5b9f\u6570\u89e3\u3092\u3082\u3064<\/li>\n<li>\u5224\u5225\u5f0f\\(D=0\\)\uff1a1\u3064\u306e\u5b9f\u6570\u89e3\u3092\u3082\u3064\uff08\u91cd\u89e3\uff09<\/li>\n<li>\u5224\u5225\u5f0f\\(D&lt;0\\)\uff1a\u5b9f\u6570\u89e3\u3092\u3082\u305f\u306a\u3044<\/li>\n<\/ul>\n<p>\u3053\u306e\u3088\u3046\u306b\u3001\u5224\u5225\u5f0f\u3092\u78ba\u8a8d\u3059\u308b\u3053\u3068\u3067\u7b54\u3048\u306e\u6570\u304c\u308f\u304b\u308a\u307e\u3059\u3002<\/p>\n<h3>\u306a\u305c\u5224\u5225\u5f0f\u3067\u5b9f\u6570\u89e3\u306e\u500b\u6570\u304c\u308f\u304b\u308b\u306e\u304b<\/h3>\n<p>\u305d\u308c\u3067\u306f\u3001\u306a\u305c\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u7b54\u3048\u306e\u6570\u304c\u308f\u304b\u308b\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u3053\u306e\u7406\u7531\u306b\u3064\u3044\u3066\u3001\u5e73\u65b9\u6839\u306e\u6027\u8cea\u3092\u601d\u3044\u51fa\u305b\u3070\u7406\u89e3\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u5e73\u65b9\u6839\u3092\u5229\u7528\u3059\u308b\u5834\u5408\u3001\u30eb\u30fc\u30c8\u5185\u306e\u6570\u5b57\u304c\u30de\u30a4\u30ca\u30b9\u306b\u306a\u3063\u3066\u306f\u3044\u3051\u307e\u305b\u3093\u3002\u4f8b\u3048\u3070\u3001\\(\\sqrt{-2}\\)\u3068\u3044\u3046\u6570\u5b57\u306f\u5b58\u5728\u3057\u307e\u305b\u3093\u3002\u305d\u3053\u3067\u89e3\u306e\u516c\u5f0f\u3092\u307f\u308b\u3068\u3001\u30eb\u30fc\u30c8\u306e\u4e2d\u306b\\(b^2-4ac\\)\u304c\u3042\u308a\u307e\u3059\u3002\u3064\u307e\u308a<span style=\"color: #0000ff;\">\\(b^2-4ac\\)\u306e\u7b54\u3048\u304c\u30de\u30a4\u30ca\u30b9\u306e\u5834\u5408\u3001\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3057\u3066\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u305b\u3093\u3002<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh3.jpg\" alt=\"\" width=\"500\" height=\"188\" class=\"aligncenter size-full wp-image-4765\" \/><\/p>\n<p>\u5224\u5225\u5f0f\\(D\\)\u306e\u7b54\u3048\u304c\u30de\u30a4\u30ca\u30b9\u306e\u5834\u5408\u306f\u89e3\u306e\u516c\u5f0f\u3067\u7b54\u3048\u304c\u5b58\u5728\u3057\u306a\u3044\u305f\u3081\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306f\u7b54\u3048\u3092\u3082\u3061\u307e\u305b\u3093\u3002\u4e00\u65b9\u3067\u5224\u5225\u5f0f\\(D\\)\u304c\u30d7\u30e9\u30b9\u306e\u5834\u5408\u3001\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u30672\u3064\u306e\u7570\u306a\u308b\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u305d\u308c\u3067\u306f\u3001\u5224\u5225\u5f0f\u3092\u5229\u7528\u3057\u3066\\(D=0\\)\u3068\u306a\u308b\u5834\u5408\u306f\u3069\u306e\u3088\u3046\u306b\u8003\u3048\u308c\u3070\u3044\u3044\u306e\u3067\u3057\u3087\u3046\u304b\u3002\\(D=0\\)\u3067\u306f\\(b^2-4ac=0\\)\u306b\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u89e3\u306e\u516c\u5f0f\u3067\\(\u00b1\\)\u306e\u90e8\u5206\u304c\u6d88\u3048\u307e\u3059\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh4.jpg\" alt=\"\" width=\"400\" height=\"218\" class=\"aligncenter size-full wp-image-4766\" \/><\/p>\n<p>\\(\u00b1\\)\u304c\u6d88\u3048\u308b\u305f\u3081\u3001\u7b54\u3048\u306f\u4e00\u3064\u306e\u307f\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u304c\u3001\\(D=0\\)\u306e\u5834\u5408\u306b\u7b54\u3048\u304c\u4e00\u3064\u306b\u306a\u308b\u7406\u7531\u3067\u3059\u3002\u306a\u304a\u7b54\u3048\u304c\u4e00\u3064\u306e\u5834\u5408\u3001\u91cd\u89e3\u3068\u547c\u3070\u308c\u307e\u3059<\/p>\n<h3>\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3067\u304d\u308b\u306e\u306f\u4e8c\u6b21\u65b9\u7a0b\u5f0f<\/h3>\n<p>\u306a\u304a\u3001\u89e3\u306e\u516c\u5f0f\u3092\u4e00\u6b21\u65b9\u7a0b\u5f0f\u3067\u5229\u7528\u3057\u3066\u306f\u3044\u3051\u307e\u305b\u3093\u3002\u4e8c\u6b21\u65b9\u7a0b\u5f0f\uff08\\(a\u22600\\)\uff09\u3067\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u5f0f\u30672\u3064\u306e\u5b9f\u6570\u89e3\u3092\u3082\u3064\\(a\\)\u306e\u7bc4\u56f2\u306f\u4f55\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n<ul>\n<li>\\(ax^2+(2a-1)x+a=0\\)<\/li>\n<\/ul>\n<p>\u5224\u5225\u5f0f\\(D&gt;0\\)\u3092\u5229\u7528\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\\(D=b^2-4ac&gt;0\\)<\/p>\n<p>\u4ee3\u5165\u3059\u308b\u3068<\/p>\n<p>\\((2a-1)^2-4\u00d7a\u00d7a&gt;0\\)<\/p>\n<p>\\((4a^2-4a+1)-4a^2&gt;0\\)<\/p>\n<p>\\(-4a+1&gt;0\\)<\/p>\n<p>\\(-4a&gt;-1\\)<\/p>\n<p>\\(a&lt;\\displaystyle\\frac{1}{4}\\)<\/p>\n<p>\u305f\u3060\u3001\u7b54\u3048\u3092\\(a&lt;\\displaystyle\\frac{1}{4}\\)\u306b\u3059\u308b\u3068\u9593\u9055\u3044\u3067\u3059\u3002\u306a\u305c\u9593\u9055\u3044\u306b\u306a\u308b\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u305d\u306e\u7406\u7531\u3068\u3057\u3066\u3001\\(a=0\\)\u306e\u3068\u304d\u306b\u5148\u307b\u3069\u306e\u5f0f\u304c\u4e00\u6b21\u65b9\u7a0b\u5f0f\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u304b\u3089\u3067\u3059\u3002\u305d\u306e\u305f\u3081\u3001\\(a=0\\)\u3092\u9664\u304b\u306a\u3051\u308c\u3070\u3044\u3051\u307e\u305b\u3093\u3002<\/p>\n<p><strong>\u30fb\\(a=0\\)\u306e\u5834\u5408<\/strong><\/p>\n<p>\\(ax^2+(2a+1)x+a=0\\)<\/p>\n<p>\\(x=0\\)<\/p>\n<p>\u65b9\u7a0b\u5f0f\u306f\u4e00\u3064\u306e\u89e3\u3092\u3082\u3061\u3001\u4e8c\u3064\u306e\u89e3\u3092\u3082\u3061\u307e\u305b\u3093\u3002\u305d\u306e\u305f\u3081\u3001\\(a\u22600\\)\u3068\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u7b54\u3048\u306f\u4ee5\u4e0b\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\\(a&lt;0,0&lt;a&lt;\\displaystyle\\frac{1}{4}\\)<\/p>\n<h2>\u30b0\u30e9\u30d5\u306e\u4e8c\u6b21\u95a2\u6570\u3001\u5224\u5225\u5f0f\u306e\u95a2\u4fc2<\/h2>\n<p>\u6b21\u306b\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3067\u306f\u306a\u304f\u3001\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3057\u307e\u3057\u3087\u3046\u3002\u4e8c\u6b21\u95a2\u6570\u3067\u306f\u30b0\u30e9\u30d5\u3092\u63cf\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u307e\u305f\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308c\u3070\u3001\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u304c\\(x\\)\u8ef8\u3068\u306e\u4ea4\u70b9\u3092\u3044\u304f\u3064\u3082\u3064\u306e\u304b\u308f\u304b\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u5177\u4f53\u7684\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh5.jpg\" alt=\"\" width=\"600\" height=\"226\" class=\"aligncenter size-full wp-image-4767\" \/><\/p>\n<p>\u306a\u305c\u3001\u3053\u306e\u3088\u3046\u306b\u5224\u65ad\u3067\u304d\u308b\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u3053\u306e\u7406\u7531\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u3001\u4e8c\u6b21\u95a2\u6570\u306e\u5f0f\u3092\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\u3002\u4e8c\u6b21\u95a2\u6570\u306f\u4ee5\u4e0b\u306e\u5f0f\u3067\u8868\u3055\u308c\u307e\u3059\u3002<\/p>\n<ul>\n<li>\\(y=ax^2+bc+c\\)<\/li>\n<\/ul>\n<p>\u6b21\u306b\\(y=0\\)\u3092\u4ee3\u5165\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u305d\u3046\u3059\u308b\u3068\u3001\\(ax^2+bc+c=0\\)\u306b\u306a\u308a\u307e\u3059\u3002\\(ax^2+bc+c=0\\)\u306f\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3067\u3042\u308a\u3001\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u5b9f\u6570\u89e3\u304c\u3044\u304f\u3064\u3042\u308b\u306e\u304b\u8abf\u3079\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><span style=\"color: #0000ff;\">\u4e8c\u6b21\u95a2\u6570\u3067\\(y=0\\)\u3068\u3044\u3046\u306e\u306f\u3001\\(x\\)\u8ef8\u3092\u8868\u3057\u307e\u3059\u3002<\/span>\\(x\\)\u8ef8\u4e0a\u306b\u3042\u308b\u6570\u5b57\u306f\u3059\u3079\u3066\\(y=0\\)\u306b\u306a\u308a\u307e\u3059\u3002\u307e\u305f\\(D&gt;0\\)\u3067\u3042\u308c\u3070\u3001\\(y=0\\)\u306e\u3068\u304d2\u3064\u306e\u7b54\u3048\u304c\u3042\u308b\u3053\u3068\u3092\u610f\u5473\u3057\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u5834\u5408\u3001\\(y=0\\)\u306e\u3068\u304d\u3001\u7b54\u3048\u304c\u3044\u304f\u3064\u3042\u308b\u306e\u304b\u8abf\u3079\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh6.jpg\" alt=\"\" width=\"600\" height=\"167\" class=\"aligncenter size-full wp-image-4768\" \/><\/p>\n<p>\u4e00\u65b9\u3067\\(D=0\\)\u306e\u5834\u5408\u3001\\(y=0\\)\u306e\u3068\u304d\u306b\u4e00\u3064\u306e\u7b54\u3048\u304c\u51fa\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u4e8c\u6b21\u95a2\u6570\u306f\\(x\\)\u8ef8\u4e0a\u3067\u63a5\u3057\u307e\u3059\u3002\u307e\u305f\\(D&lt;0\\)\u306e\u5834\u5408\u3001\\(y=0\\)\u306e\u3068\u304d\u306b\u7b54\u3048\u304c\u51fa\u307e\u305b\u3093\u3002\u3064\u307e\u308a\u3001\u4e8c\u6b21\u95a2\u6570\u306f\\(x\\)\u8ef8\u3068\u306e\u4ea4\u70b9\u304c\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p><strong>\u30fb\\(x\\)\u8ef8\u306b\u63a5\u3059\u308b\u5834\u5408\u306e\u7b54\u3048\u306e\u51fa\u3057\u65b9<\/strong><\/p>\n<p>\u305d\u308c\u3067\u306f\u3001\u5b9f\u969b\u306b\u554f\u984c\u3092\u89e3\u3044\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u4ee5\u4e0b\u306e\u4e8c\u6b21\u95a2\u6570\u306b\u3064\u3044\u3066\u3001\\(x\\)\u8ef8\u306b\u63a5\u3059\u308b\\(k\\)\u306e\u5024\u306f\u4f55\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n<ul>\n<li>\\(x^2+(k-3)x+k\\)<\/li>\n<\/ul>\n<p><span style=\"color: #0000ff;\">\\(x\\)\u8ef8\u306b\u63a5\u3059\u308b\u3068\u3044\u3046\u306e\u306f\u3001\\(x\\)\u8ef8\u3068\u306e\u4ea4\u70b9\u304c1\u3064\u3067\u3042\u308b\u3053\u3068\u3092\u610f\u5473\u3057\u307e\u3059\u3002<\/span>\u3064\u307e\u308a\u3001\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3068\\(D=0\\)\u306b\u306a\u308a\u307e\u3059\u3002\u305d\u3053\u3067\u3001\\(D=0\\)\u306b\u306a\u308b\\(k\\)\u3092\u6c42\u3081\u307e\u3057\u3087\u3046\u3002\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\\(D= b^2-4ac=0\\)<\/p>\n<p>\u4ee3\u5165\u3059\u308b\u3068<\/p>\n<p>\\((k-3)^2-4\u00d71\u00d7k=0\\)<\/p>\n<p>\\((k^2-6k+9)-4k=0\\)<\/p>\n<p>\\(k^2-10k+9=0\\)<\/p>\n<p>\\((k-1)(k-9)=0\\)<\/p>\n<p>\u3053\u3046\u3057\u3066\u3001\\(k=1\\)\u307e\u305f\u306f\\(k=9\\)\u306e\u3068\u304d\u3001\u4e8c\u6b21\u95a2\u6570\u306f\\(x\\)\u8ef8\u3067\u63a5\u3059\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<h3>\u653e\u7269\u7dda\u3068\u76f4\u7dda\u306e\u5171\u6709\u70b9\u3068\u305d\u306e\u500b\u6570<\/h3>\n<p>\u3053\u3053\u307e\u3067\u306e\u5185\u5bb9\u3092\u7406\u89e3\u3059\u308c\u3070\u3001\u653e\u7269\u7dda\uff08\u4e8c\u6b21\u95a2\u6570\uff09\u3068\u76f4\u7dda\uff08\u4e00\u6b21\u95a2\u6570\uff09\u3068\u306e\u5171\u6709\u70b9\u306e\u500b\u6570\u3084\u5ea7\u6a19\u3092\u898b\u3064\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u4e8c\u6b21\u95a2\u6570\u3068\u4e00\u6b21\u95a2\u6570\u306e\u4ea4\u70b9\u3092\u898b\u3064\u3051\u308b\u65b9\u6cd5\u3068\u3057\u3066\u306f\u3001\u9023\u7acb\u65b9\u7a0b\u5f0f\u3092\u89e3\u3051\u3070\u3044\u3044\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u6b21\u306e\u4e8c\u6b21\u95a2\u6570\u3068\u4e00\u6b21\u95a2\u6570\u304c\u5171\u6709\u70b9\u3092\u3082\u3064\u3068\u304d\u3001\\(k\\)\u306e\u7bc4\u56f2\u3092\u6c42\u3081\u307e\u3057\u3087\u3046\u3002<\/p>\n<ul>\n<li>\\(y=x^2\\)<\/li>\n<li>\\(y=-x+k\\)<\/li>\n<\/ul>\n<p>\u3053\u306e\u554f\u984c\u3092\u89e3\u304f\u305f\u3081\u3001\u4ee5\u4e0b\u306e\u9023\u7acb\u65b9\u7a0b\u5f0f\u3092\u4f5c\u308a\u307e\u3059\u3002<\/p>\n<p>\\(\\begin{eqnarray} \\left\\{\\begin{array}{l}y=x^2\\\\y=-x+k\\end{array}\\right.\\end{eqnarray}\\)<\/p>\n<p>\u305d\u3053\u3067\u3001\\(y=-x+k\\)\u3092\\(y=x^2\\)\u306b\u4ee3\u5165\u3057\u307e\u3057\u3087\u3046\u3002\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\\(x^2=-x+k\\)<\/p>\n<p>\\(x^2+x-k=0\\)<\/p>\n<p><span style=\"color: #0000ff;\">\u3053\u306e\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u304c\u89e3\u3092\u3082\u3064\u5834\u5408\u3001\u4e8c\u6b21\u95a2\u6570\u3068\u4e00\u6b21\u95a2\u6570\u306f\u5171\u6709\u70b9\u3092\u3082\u3061\u307e\u3059\u3002<\/span>\u89e3\u3092\u3082\u3064\u305f\u3081\u306b\u306f\u3001\u5224\u5225\u5f0f\u306f\\(D\u22670\\)\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u5224\u5225\u5f0f\u3092\u5229\u7528\u3057\u3066\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u8a08\u7b97\u3057\u307e\u3059\u3002<\/p>\n<p>\\(D=b^2-4ac\u22670\\)<\/p>\n<p>\u4ee3\u5165\u3059\u308b\u3068<\/p>\n<p>\\(1^2-4\u00d71\u00d7(-k)\u22670\\)<\/p>\n<p>\\(1+4k\u22670\\)<\/p>\n<p>\\(k\u2267-\\displaystyle\\frac{1}{4}\\)<\/p>\n<p>\u3053\u3046\u3057\u3066\u3001\\(k\u2267-\\displaystyle\\frac{1}{4}\\)\u304c\u7b54\u3048\u3067\u3042\u308b\u3068\u308f\u304b\u308a\u307e\u3059\u3002<\/p>\n<h3>\u306a\u305c\u4ee3\u5165\u306b\u3088\u3063\u3066\u653e\u7269\u7dda\u3068\u76f4\u7dda\u306e\u4ea4\u70b9\u304c\u308f\u304b\u308b\u306e\u304b<\/h3>\n<p>\u305d\u308c\u3067\u306f\u3001\u306a\u305c\u4ee3\u5165\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u653e\u7269\u7dda\u3068\u76f4\u7dda\u306e\u4ea4\u70b9\u3092\u6c42\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u3053\u308c\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u3001\u5148\u307b\u3069\u306e\u9023\u7acb\u65b9\u7a0b\u5f0f\u3092\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\\(\\begin{eqnarray} \\left\\{\\begin{array}{l}y=x^2\\\\y=-x+k\\end{array}\\right.\\end{eqnarray}\\)<\/p>\n<p>\u305d\u306e\u5f8c\u3001\\(y=-x+k\\)\u3092\\(y=x^2\\)\u306b\u4ee3\u5165\u3057\u307e\u3057\u305f\u3002\u307e\u305f<span style=\"color: #ff0000;\">\u9023\u7acb\u65b9\u7a0b\u5f0f\u3067\u4ee3\u5165\u3059\u308b\u3068\u3044\u3046\u306e\u306f\u3001\u5f15\u304d\u7b97\u3092\u3059\u308b\u306e\u3068\u610f\u5473\u304c\u540c\u3058\u3067\u3059\u3002<\/span>\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3001\u5f15\u304d\u7b97\u3092\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\\(y\\)\u3092\u6d88\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh7.jpg\" alt=\"\" width=\"423\" height=\"211\" class=\"aligncenter size-full wp-image-4769\" \/><\/p>\n<p>\u305d\u3053\u3067\u3001\\(y=x^2\\)\u306e\u95a2\u6570\u3092\\(y=A\\)\u3068\u3057\u307e\u3057\u3087\u3046\u3002\u307e\u305f\u3001\\(y=-x+k\\)\u306e\u95a2\u6570\u3092\\(y=B\\)\u3068\u3057\u307e\u3057\u3087\u3046\u3002\u305d\u3046\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u65b0\u305f\u306a\u95a2\u6570\u3092\u4f5c\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<ul>\n<li>\\(y&#8217;=A-B\\)<\/li>\n<\/ul>\n<p>\u3053\u306e\u3088\u3046\u306b\u65b0\u305f\u306a\u95a2\u6570\u3092\u4f5c\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u3001\u3053\u3053\u307e\u3067\u5b66\u3093\u3067\u304d\u305f\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u3092\u63cf\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\uff08\u4e0b\u56f3\u306e\u53f3\u5074\uff09\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/hatsudy.com\/jp\/wp-content\/uploads\/2022\/03\/ydfh9.jpg\" alt=\"\" width=\"550\" height=\"397\" class=\"aligncenter size-full wp-image-4770\" \/><\/p>\n<p>\u307e\u305f\\(A-B=0(y&#8217;=0)\\)\u3068\u306a\u308b\u5834\u5408\u3001\\(A=B\\)\u3068\u306a\u308a\u307e\u3059\u3002\\(A=B\\)\u3068\u3044\u3046\u306e\u306f\u3001\u95a2\u6570A\u3068\u95a2\u6570B\u306e\u5ea7\u6a19\u304c\u540c\u3058\u306b\u306a\u308b\u3053\u3068\u3092\u610f\u5473\u3057\u307e\u3059\u3002<span style=\"color: #0000ff;\">\u540c\u3058\u5ea7\u6a19\u3068\u3044\u3046\u306e\u306f\u3001\u3064\u307e\u308a\u4ea4\u70b9\u3092\u610f\u5473\u3057\u307e\u3059\u3002<\/span><\/p>\n<p>\u305d\u3053\u3067\\(y&#8217;=A-B\\)\u306e\u95a2\u6570\u306b\u3064\u3044\u3066\u3001\\(y&#8217;=0\\)\u306b\u306a\u308b\u6761\u4ef6\u3092\u63a2\u3057\u307e\u3059\u3002\\(y&#8217;=0\\)\u3068\u3044\u3046\u306e\u306f\u3001\\(y&#8217;=A-B\\)\u306e\u95a2\u6570\u304c\\(x\\)\u8ef8\u3068\u5171\u6709\u70b9\u3092\u3082\u3064\u3053\u3068\u3092\u610f\u5473\u3057\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u3001\\(y=-x+k\\)\u3068\\(y=x^2\\)\u304c\u4ea4\u70b9\u3092\u3082\u3064\u6761\u4ef6\u3092\u6c42\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<h2>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3068\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b<\/h2>\n<p>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306e\u7b54\u3048\u3092\u51fa\u3059\u65b9\u6cd5\u306e\u4e00\u3064\u3068\u3057\u3066\u89e3\u306e\u516c\u5f0f\u304c\u3042\u308a\u307e\u3059\u3002\u89e3\u306e\u516c\u5f0f\u306f\u5f0f\u306e\u4e2d\u306b\u5e73\u65b9\u6839\u3092\u3082\u3061\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u30eb\u30fc\u30c8\u5185\u306e\u6570\u5b57\u304c\u30de\u30a4\u30ca\u30b9\u306e\u5834\u5408\u3001\u305d\u306e\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u306f\u89e3\u3092\u3082\u3061\u307e\u305b\u3093\u3002<\/p>\n<p>\u3053\u306e\u6027\u8cea\u3092\u5229\u7528\u3057\u3066\u3001\u79c1\u305f\u3061\u306f\u5224\u5225\u5f0f\\(D\\)\u3092\u5229\u7528\u3057\u307e\u3059\u3002\\(D&gt;0\\)\u306e\u5834\u5408\u30012\u3064\u306e\u7570\u306a\u308b\u89e3\u3092\u3082\u3061\u307e\u3059\u3002\u307e\u305f\\(D=0\\)\u306e\u5834\u5408\u3001\u7b54\u3048\u306f1\u3064\u3067\u3059\u3002\u4e00\u65b9\u3067\\(D&lt;0\\)\u306e\u5834\u5408\u3001\u89e3\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u5224\u5225\u5f0f\u304c\u30d7\u30e9\u30b9\u306a\u306e\u304b\u30de\u30a4\u30ca\u30b9\u306a\u306e\u304b\u306b\u3088\u3063\u3066\u3001\u7b54\u3048\u306e\u6570\u304c\u5909\u308f\u308a\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u3089\u306e\u5185\u5bb9\u3092\u5b66\u3079\u3070\u3001\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u4e8c\u6b21\u95a2\u6570\u3067\u306f\u30b0\u30e9\u30d5\u3092\u63cf\u304d\u307e\u3059\u3002\\(y=0\\)\u306e\u5834\u5408\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3068\u540c\u3058\u5f0f\u306b\u306a\u308a\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u3067\\(x\\)\u8ef8\u3068\u306e\u4ea4\u70b9\u306e\u6570\u3092\u898b\u5206\u3051\u308b\u3088\u3046\u306b\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\u4e8c\u6b21\u95a2\u6570\u3067\u5224\u5225\u5f0f\u3092\u5229\u7528\u3059\u308b\u30b1\u30fc\u30b9\u306f\u591a\u3044\u3067\u3059\u3002\u3069\u306e\u3088\u3046\u306a\u3068\u304d\u3001\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3084\u4e8c\u6b21\u95a2\u6570\u3067\u7b54\u3048\u304c\u5b58\u5728\u3059\u308b\u306e\u304b\u5224\u5225\u5f0f\u3092\u7528\u3044\u3066\u5224\u65ad\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e8c\u6b21\u65b9\u7a0b\u5f0f\u3092\u89e3\u304f\u3068\u304d\u3001\u7b54\u3048\u304c\u6574\u6570\u3067\u51fa\u306a\u3044\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u5834\u5408\u3001\u89e3\u306e\u516c\u5f0f\u3092\u4f7f\u3044\u307e\u3059\u3002\u89e3\u306e\u516c\u5f0f\u3092\u5229\u7528\u3059\u308c\u3070\u3001\u7b54\u3048\u306b\u5e73\u65b9\u6839\u304c\u542b\u307e\u308c\u3066\u3044\u3066\u3082\u7b54\u3048\u3092\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002 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