![](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/07\/nurseman_question.png\")
<\/p>\n<\/p>\n
![](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/07\/3588888.jpg\")
<\/p>\n
<\/p>\n
- \n
- \u672c\u8a18\u4e8b\u306e\u5185\u5bb9<\/strong><\/li>\n<\/ul>\n<\/div>\n\n\n
- \n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9<\/strong><\/a><\/li>\n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u554f\u984c<\/strong><\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n
<\/p>\n
\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u3092\u901f\u653b\u3067\u66f8\u304f\u624b\u9806<\/h2>\n
<\/p>\n
\n- \n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306b\u5fc5\u8981\u306a\u60c5\u5831<\/strong><\/span><\/li>\n<\/ul>\n<\/div>\n\n\n
- \n
- \u539f\u70b9<\/li>\n
- \u9802\u70b9\u5ea7\u6a19<\/li>\n
- \u30b0\u30e9\u30d5\u306e\u8ef8<\/li>\n
- x\u8ef8\u3068\u30b0\u30e9\u30d5\u306e\u4ea4\u70b9\uff08x\u5207\u7247\uff09<\/li>\n
- y\u8ef8\u3068\u30b0\u30e9\u30d5\u306e\u4ea4\u70b9\uff08y\u5207\u7247\uff09<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
<\/p>\n
\u3076\u3063\u3061\u3083\u3051\u3001\u4e0a\u8a185\u3064\u306e\u60c5\u5831\u304c\u660e\u78ba\u306b\u793a\u3055\u308c\u3066\u3044\u308c\u3070\u3001\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9\u306f\u306a\u3093\u3067\u3082OK\u3002<\/p>\n
<\/p>\n
\u305f\u3060\u3057\u4eca\u56de\u306f\u3001\u3088\u308a\u52b9\u7387\u7684\u306b\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u3092\u66f8\u304f\u624b\u9806\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/strong><\/p>\n
\u624b\u9806\u306f\u5168\u90e8\u30675\u3064\u3042\u308a\u307e\u3059\u3002<\/strong><\/p>\n
<\/p>\n
\n- \n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9<\/strong><\/span><\/li>\n<\/ul>\n<\/div>\n\n\n
- \n
- \u624b\u9806\u2460\uff1a\u5e73\u65b9\u5b8c\u6210\u3067\u9802\u70b9\u306e\u300c\u5ea7\u6a19\u300d\u300c\u8ef8\u300d\u3092\u6c42\u3081\u308b<\/li>\n
- \u624b\u9806\u2461\uff1a$x^2$ \u306e\u4fc2\u6570\u3092\u78ba\u8a8d\u3057\u300c\u4e0a\u51f8\u300d\u304b\u300c\u4e0b\u51f8\u300d\u304b\u3092\u5224\u65ad<\/li>\n
- \u624b\u9806\u2462\uff1a\u3053\u3053\u307e\u3067\u3067\u5206\u304b\u3063\u305f\u3053\u3068\u3092\u56f3\u306b\u8868\u3059<\/li>\n
- \u624b\u9806\u2463\uff1a\u300c\u9802\u70b9\u300d\u3068\u300cy\u8ef8\u300d\u306e\u95a2\u4fc2\u3092\u56f3\u306b\u66f8\u304d\u8fbc\u3080<\/li>\n
- \u624b\u9806\u2464\uff1a\u300c\u9802\u70b9\u300d\u3068\u300cx\u8ef8\u300d\u306e\u95a2\u4fc2\u3092\u56f3\u306b\u66f8\u304d\u8fbc\u3080<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n\n
![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u4e00\u898b \u8907\u96d1\u3067\u3059\u304c\u3001\u3084\u3084\u3053\u3057\u3044\u8a08\u7b97\u306f\u4e00\u5207\u3042\u308a\u307e\u305b\u3093\u3002
\n\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306f\u3001\u6163\u308c\u308c\u307010\u79d2\u307b\u3069\u3067\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3088\uff01<\/div>\n<\/div>\n<\/p>\n
\u3053\u3053\u304b\u3089\u306f\u4ee5\u4e0b\u306e\u4e8c\u6b21\u95a2\u6570\u3092\u4f7f\u3063\u3066\u3001\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9\u3092\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n
<\/p>\n
$${\\large y=x^2+6x+8}$$<\/p>\n
<\/p>\n
<\/p>\n
\u624b\u9806\u2460\uff1a\u5e73\u65b9\u5b8c\u6210\u3067\u9802\u70b9\u306e\u300c\u5ea7\u6a19\u300d\u300c\u8ef8\u300d\u3092\u6c42\u3081\u308b<\/h3>\n
$${\\large y=x^2+6x+8}$$<\/p>\n
<\/p>\n
\u307e\u305a\u306f\u4e8c\u6b21\u95a2\u6570\u306e\u9802\u70b9\u5ea7\u6a19<\/strong>\u3068\u8ef8<\/strong>\u3092\u6c42\u3081\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n
\u5e73\u65b9\u5b8c\u6210\u3092\u4f7f\u3063\u3066\u3082\u3088\u3057\u3001\u516c\u5f0f\u3092\u5229\u7528\u3057\u3066\u3082\u3088\u3057\u306a\u306e\u3067\u3001\u304a\u597d\u304d\u306a\u65b9\u6cd5\u3092\u9078\u629e\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/p>\n
\n\n\u3010\u5e73\u65b9\u5b8c\u6210\u3059\u308b\u65b9\u6cd5\u3011<\/strong><\/p>\n
$$y=x^2+6x+8$$<\/p>\n
$$=(x+3)^2-9+8$$<\/p>\n
$$=(x+3)^2-1$$<\/p>\n
<\/p>\n
\u3088\u3063\u3066\u9802\u70b9\u3001\u8ef8\u306f\u305d\u308c\u305e\u308c<\/p>\n
$$\\color{red}\u9802\u70b9\\color{black}\uff1a(-3,-1)$$<\/p>\n
$$\\color{red}\u8ef8\\color{black}\uff1ax=-3$$<\/p>\n<\/div>\n<\/div>\n
<\/p>\n
\n\n\u3010\u516c\u5f0f\u3092\u5229\u7528\u3059\u308b\u65b9\u6cd5\u3011<\/strong><\/p>\n
$y=ax^2+bx+c$ \u306e\u9802\u70b9\u306ex\u5ea7\u6a19\uff08\u8ef8\uff09\u304c\u6b21\u306e\u3088\u3046\u306b\u8868\u3055\u308c\u308b\u3053\u3068\u3092\u5229\u7528\u3059\u308b\u3002<\/p>\n
$$x=-\\dfrac{b}{2a}$$<\/p>\n
\u3088\u3063\u3066\u3001\u8ef8\u306f<\/p>\n
$$x=-\\dfrac{6}{2(1)}$$<\/p>\n
$$\\color{red}\u8ef8\\color{black}\uff1ax=-3$$<\/p>\n
<\/p>\n
$x=-3$ \u3092 $y=x^2+6x+8$ \u306b\u4ee3\u5165\u3059\u308b\u3068<\/p>\n
$$y=(-3)^2+6(-3)+8$$<\/p>\n
$$y=-1$$<\/p>\n
\u3088\u3063\u3066\u9802\u70b9\u5ea7\u6a19\u306f<\/p>\n
$$\\color{red}\u9802\u70b9\\color{black}\uff1a(-3,-1)$$<\/p>\n<\/div>\n<\/div>\n
<\/p>\n
\u624b\u9806\u2461\uff1a\u4e8c\u6b21\u306e\u4fc2\u6570\u3092\u78ba\u8a8d\u3057\u300c\u4e0a\u51f8\u300d\u304b\u300c\u4e0b\u51f8\u300d\u304b\u3092\u5224\u65ad<\/h3>\n
$${\\large y=x^2+6x+8}$$<\/p>\n
<\/p>\n
\u7d9a\u3044\u3066\u306f $x^2$ \u306e\u4fc2\u6570\u3092\u78ba\u8a8d\u3057\u3001\u30b0\u30e9\u30d5\u306e\u5411\u304d\u304c\u300c\u4e0a\u51f8\u300d\u304b\u300c\u4e0b\u51f8\u300d<\/strong>\u304b\u3092\u5224\u65ad\u3057\u307e\u3059\u3002<\/p>\n
\u4eca\u56de\u306e\u5834\u5408\u3001$x^2$ \u306e\u4fc2\u6570\u306f $1$ \u3067\u3059\u306e\u3067\u3001\u30b0\u30e9\u30d5\u306e\u5411\u304d\u306f\u300c\u4e0b\u51f8\u300d\u3067\u3059\u306d\uff01<\/p>\n
<\/p>\n
\n\n![]()
<\/p>\n\u304e\u3082\u3093\u541b<\/div>\n<\/div>\n\u4e8c\u6b21\u95a2\u6570\u306e\u5834\u5408\u3001$x^2$\u306e\u4fc2\u6570\u304c\u6b63\u306e\u6570\u306a\u3089\u300c\u4e0b\u51f8\u300d\u3001\u8ca0\u306e\u6570\u306a\u3089\u300c\u4e0a\u51f8\u300d\u306b\u306a\u308b\u3093\u3060\u3063\u305f\u3088\u306d\uff01<\/div>\n<\/div>\n<\/p>\n
\u624b\u9806\u2462\uff1a\u3053\u3053\u307e\u3067\u3067\u5206\u304b\u3063\u305f\u3053\u3068\u3092\u56f3\u306b\u8868\u3059<\/h3>\n
\u3053\u3053\u304b\u3089\u306f\u3001\u3044\u3088\u3044\u3088\u5b9f\u969b\u306b\u30b0\u30e9\u30d5\u3092\u66f8\u3044\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n
\u3053\u3053\u307e\u3067\u306b\u5206\u304b\u3063\u3066\u3044\u308b\u60c5\u5831\u306f\u6b21\u306e\u901a\u308a\u3002<\/p>\n
<\/p>\n
\n\n- \n
- \u9802\u70b9\u5ea7\u6a19\u306f $(-3,-1)$<\/li>\n
- \u30b0\u30e9\u30d5\u306e\u8ef8\u306f $x=-3$<\/li>\n
- \u30b0\u30e9\u30d5\u306e\u5411\u304d\u306f\u4e0b\u51f8<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
<\/p>\n
\u3053\u308c\u3089\u306e\u60c5\u5831\u3092\u56f3\u306b\u8868\u3059\u3068\u3001\u3001\u3001<\/p>\n
<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\n\n![]()
<\/p>\n\u304e\u3082\u3093\u541b<\/div>\n<\/div>\n\u3042\u308c\uff1fx\u8ef8\u3084y\u8ef8\u304c\u3042\u308a\u307e\u305b\u3093\u3088\uff01<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\nx\u8ef8\u3084y\u8ef8\u306f\u3001\u30b0\u30e9\u30d5\u4f5c\u6210\u306e\u300c\u6700\u5f8c\u306e\u5de5\u7a0b\u300d\u3067\u3059\u3002<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u5207\u7247\uff08\u8ef8\u3068\u30b0\u30e9\u30d5\u306e\u4ea4\u70b9\uff09\u306e\u60c5\u5831\u304c\u5206\u304b\u3063\u3066\u3044\u306a\u3044\u4eca\u306e\u6bb5\u968e\u3067\u300cx\u8ef8\u30fby\u8ef8\u300d\u3092\u66f8\u3044\u3066\u3057\u307e\u3046\u3068\u3001\u5f8c\u3067\u4fee\u6b63\u3059\u308b\u5fc5\u8981\u304c\u51fa\u3066\u304d\u304b\u306d\u306a\u3044\u306e\u3067\uff01<\/div>\n<\/div>\n<\/p>\n
\u624b\u9806\u2463\uff1a\u300c\u30b0\u30e9\u30d5\u3068y\u8ef8\u300d\u306e\u95a2\u4fc2\u3092\u56f3\u306b\u66f8\u304d\u8fbc\u3080<\/h3>\n
\u7d9a\u3044\u3066\u306f\u3001\u30b0\u30e9\u30d5\u3068y\u8ef8\u306e\u95a2\u4fc2\u3092\u5148\u307b\u3069\u306e\u56f3\u306b\u66f8\u304d\u8fbc\u3093\u3067\u3044\u304d\u307e\u3059\u3002<\/p>\n
<\/p>\n
\n\n\u3010\u66f8\u304d\u8fbc\u3080\u60c5\u5831\u3011<\/strong><\/p>\n
- \n
- \u30b0\u30e9\u30d5\u3068y\u8ef8\u306e\u4ea4\u70b9\uff08y\u5207\u7247\uff09\u306e\u4f4d\u7f6e<\/li>\n
- \u30b0\u30e9\u30d5\u306e\u8ef8\u3068y\u8ef8\u306e\u5927\u5c0f\u95a2\u4fc2<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
<\/p>\n
y\u5207\u7247\u306e\u5ea7\u6a19\u306f\u3001$y=x^2+6x+8$ \u306b $x=0$ \u3092\u4ee3\u5165\u3059\u308b\u3053\u3068\u3067\u6c42\u3081\u3089\u308c\u307e\u3059\u3002<\/p>\n
$$y=(0)^2+6(0)+8$$<\/p>\n
$$y=8\\color{red}\uff08y\u5207\u7247\uff09$$<\/p>\n
<\/p>\n
\u30b0\u30e9\u30d5\u306e\u8ef8\u306f $x=-3$\u3001y\u8ef8\u306f $x=0$ \u3060\u304b\u3089\u3001\u4e21\u8005\u306e\u5927\u5c0f\u95a2\u4fc2\u306f<\/p>\n
$$\u30b0\u30e9\u30d5\u8ef8<y\u8ef8\\color{red}\uff08\u5927\u5c0f\u95a2\u4fc2\uff09$$<\/p>\n
<\/p>\n
\u4ee5\u4e0a2\u3064\u306e\u60c5\u5831\u3092\u30b0\u30e9\u30d5\u306b\u66f8\u304d\u8fbc\u3080\u3068\u3001\u3001\u3001<\/p>\n
<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\u624b\u9806\u2464\uff1a\u300c\u30b0\u30e9\u30d5\u3068x\u8ef8\u300d\u306e\u95a2\u4fc2\u3092\u56f3\u306b\u66f8\u304d\u8fbc\u3080<\/h3>\n
\u6700\u5f8c\u306b\u3001\u30b0\u30e9\u30d5\u3068x\u8ef8\u306e\u95a2\u4fc2\u3092\u5148\u307b\u3069\u306e\u56f3\u306b\u66f8\u304d\u8fbc\u3093\u3067\u3044\u304d\u307e\u3059\u3002<\/p>\n
<\/p>\n
\n\n\u3010\u66f8\u304d\u8fbc\u3080\u60c5\u5831\u3011<\/strong><\/p>\n
- \n
- \u30b0\u30e9\u30d5\u3068x\u8ef8\u306e\u4ea4\u70b9\uff08x\u5207\u7247\uff09\u306e\u4f4d\u7f6e<\/li>\n
- \u9802\u70b9\u306ey\u5ea7\u6a19\u3068x\u8ef8\u306e\u5927\u5c0f\u95a2\u4fc2<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
<\/p>\n
x\u5207\u7247\u306e\u5ea7\u6a19\u306f\u3001$y=x^2+6x+8$ \u306b $y=0$ \u3092\u4ee3\u5165\u3059\u308b\u3053\u3068\u3067\u6c42\u3081\u3089\u308c\u307e\u3059\u3002<\/p>\n
$$0=x^2+6x+8$$<\/p>\n
$$0=(x+2)(x+4)$$<\/p>\n
$$x=-2,-4\\color{red}\uff08x\u5207\u7247\uff09$$<\/p>\n
<\/p>\n
\u9802\u70b9\u306ey\u5ea7\u6a19\u306f $y=-1$\u3001x\u8ef8\u306f $y=0$ \u3060\u304b\u3089\u3001\u4e21\u8005\u306e\u5927\u5c0f\u95a2\u4fc2\u306f<\/p>\n
$$\u9802\u70b9\u306ey\u5ea7\u6a19<x\u8ef8\\color{red}\uff08\u5927\u5c0f\u95a2\u4fc2\uff09$$<\/p>\n
<\/p>\n
\u4ee5\u4e0a2\u3064\u306e\u60c5\u5831\u3092\u30b0\u30e9\u30d5\u306b\u66f8\u304d\u8fbc\u3080\u3068\u3001\u3001\u3001<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
<\/p>\n
\u3053\u308c\u3067\u4e8c\u6b21\u95a2\u6570\u30b0\u30e9\u30d5\u306e\u5b8c\u6210\u3067\u3059\u3002<\/strong><\/p>\n
\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9\u3092\u307e\u3068\u3081\u308b\u3068\u3001\u3053\u3093\u306a\u611f\u3058\u3002<\/p>\n
<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\u300b\u76ee\u6b21\u306b\u623b\u308b<\/a><\/strong><\/p>\n
\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9\uff5cx\u8ef8\u3068y\u8ef8\u306f\u6700\u5f8c\u306b\u66f8\u3053\u3046<\/h2>\n
<\/p>\n
\u4eca\u56de\u7528\u610f\u3057\u305f\u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u554f\u984c\u306f2\u3064\u3002<\/p>\n
\u305c\u3072\u3001\u3044\u3063\u305f\u3093\u3053\u3053\u3067\u30b9\u30af\u30ed\u30fc\u30eb\u3092\u6b62\u3081\u3066\u3001\u554f\u984c\u306b\u30c1\u30e3\u30ec\u30f3\u30b8\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\uff01<\/p>\n
\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u3069\u3061\u3089\u3082\u9ad8\u6821\u306e\u6570\u5b66\u6559\u5e2b\u304c\u597d\u3093\u3067\u51fa\u984c\u3059\u308b\u30bf\u30a4\u30d7\u306e\u554f\u984c\u3067\u3059\u306e\u3067\u3001\u52b9\u679c\u7684\u306a\u30c6\u30b9\u30c8\u5bfe\u7b56\u306b\u3082\u306a\u308a\u307e\u3059\u3088\uff01<\/div>\n<\/div>\n<\/p>\n
\n- \n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u3092\u66f8\u3044\u3066\u307f\u3088\u3046<\/strong><\/li>\n<\/ul>\n<\/div>\n\n\n
- \n
- \u7df4\u7fd2\u554f\u984c\u2460<\/strong>
\n$y=-2x^2+x+1\u306e\u30b0\u30e9\u30d5\u3092\u66f8\u304d\u306a\u3055\u3044\u3002$<\/li>\n- \u7df4\u7fd2\u554f\u984c\u2461<\/strong>
\n$y=ax^2+bx+c\u306e\u30b0\u30e9\u30d5\u304c\u4e0b\u56f3\u306e\u3088\u3046\u306b\u8868\u3055\u308c\u308b\u3068\u304d\u3001\u6b21\u306e\u5f0f\u306e\u7b26\u53f7\u3092\u6c42\u3081\u306a\u3055\u3044\u3002$
\n$\uff081\uff09a$
\n$\uff082\uff09b$
\n$\uff083\uff09c$
\n$\uff084\uff09a+b+c$
\n$\uff085\uff09a-b+c$
\n$\uff086\uff09b^2-4ac$<\/li>\n<\/ul>\n![\"\"]()
<\/p>\n<\/div>\n<\/div>\n<\/p>\n
\u7df4\u7fd2\u554f\u984c\u2460\u306e\u89e3\u8aac<\/h3>\n
\n$y=-2x^2+x+1\u306e\u30b0\u30e9\u30d5\u3092\u66f8\u304d\u306a\u3055\u3044\u3002$<\/div>\n\u3010\u7b54\u3048\u3011\u753b\u50cf<\/div>\n<\/div>\n<\/p>\n
\u307e\u305a\u306f\u3001\u9802\u70b9\u306e\u5ea7\u6a19\u3068\u8ef8\u3092\u6c42\u3081\u3088\u3046\u3002<\/p>\n
\u4eca\u56de\u306f\u5e73\u65b9\u5b8c\u6210\u3067\u9802\u70b9\u5ea7\u6a19\u3092\u6c42\u3081\u308b\u304c\u3001\u516c\u5f0f\u3092\u5229\u7528\u3057\u3066\u6c42\u3081\u3066\u3082OK\u3002\uff08\u516c\u5f0f\u89e3\u8aac<\/a>\uff09<\/strong><\/p>\n
<\/p>\n
$$y=-2x^2+x+1$$<\/p>\n
$$=\\color{red}-2\\left(x^2-\\dfrac{1}{2}x\\right)\\color{black}+1$$<\/p>\n
$$=-2\\color{red}\\left(x-\\dfrac{1}{4}\\right)^2+2\\left(\\dfrac{1}{4}\\right)^2\\color{black}+1$$<\/p>\n
$$=-2\\left(x-\\dfrac{1}{4}\\right)^2\\color{red}+\\dfrac{9}{8}$$<\/p>\n
<\/p>\n
\u3088\u3063\u3066\u9802\u70b9\u3068\u8ef8\u306f\u305d\u308c\u305e\u308c<\/p>\n
$$\u9802\u70b9\uff1a\\left(\\dfrac{1}{4},\\dfrac{9}{8}\\right)$$<\/p>\n
$$\u8ef8\uff1ax=\\dfrac{1}{4}$$<\/p>\n
<\/p>\n
\u6b21\u306b $x^2$ \u306e\u4fc2\u6570\u3092\u78ba\u8a8d\u3057\u3001\u30b0\u30e9\u30d5\u306e\u5411\u304d\u304c\u300c\u4e0a\u306b\u51f8\u300d\u304b\u300c\u4e0b\u306b\u51f8\u300d\u304b\u3092\u5224\u65ad\u3059\u308b\u3002<\/p>\n
\u4eca\u56de\u3001$x^2$ \u306e\u4fc2\u6570\u306f $-2$ \u3060\u304b\u3089\u3001$y=-2x^2+x+1$ \u306f\u4e0a\u306b\u51f8\u306e\u30b0\u30e9\u30d5\u3067\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308b\u3002<\/p>\n
<\/p>\n
\u4ee5\u4e0a\u306e\u60c5\u5831\u3092\u56f3\u306b\u8868\u3059\u3068\u3001\u3053\u3046\u306a\u308b\u3002<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\n\n![]()
<\/p>\n\u304e\u3082\u3093\u541b<\/div>\n<\/div>\n\u3053\u306e\u6bb5\u968e\u3067\u306f\u307e\u3060\u3001x\u8ef8 y\u8ef8\u306f\u66f8\u304d\u8fbc\u307e\u306a\u3044\u65b9\u304c\u826f\u3044\u3093\u3067\u3057\u305f\u3088\u306d\uff01<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u305d\u306e\u901a\u308a\u3067\u3059\u3002
\n\u4eca\u306e\u6bb5\u968e\u3067\u66f8\u304d\u8fbc\u3080\u3068\u3001\u3042\u3068\u304b\u3089\u4fee\u6b63\u3059\u308b\u5fc5\u8981\u3082\u51fa\u3066\u304d\u3066\u3057\u307e\u3044\u307e\u3059\u306e\u3067\uff01<\/div>\n<\/div>\n<\/p>\n
\u3053\u3053\u307e\u3067\u304f\u308c\u3070\u3001\u3042\u3068\u306f\u4e0a\u8a18\u306e\u56f3\u306b\u300cx\u8ef8\u300d\u300cy\u8ef8\u300d\u3068\u306e\u95a2\u4fc2\u3092\u66f8\u304d\u8fbc\u3081\u3070\u3044\u3044\u3002<\/p>\n
<\/p>\n
- \n
- $x=0$ \u306e\u3068\u304d $y=1\uff08y\u5207\u7247=1\uff09$<\/li>\n
- \u9802\u70b9\u306ex\u5ea7\u6a19\u306f\u6b63\u306e\u6570<\/li>\n
- \u9802\u70b9\u306ey\u5ea7\u6a19\u306f\u6b63\u306e\u6570<\/li>\n<\/ul>\n
<\/p>\n
\u3053\u306e3\u70b9\u3092\u30b0\u30e9\u30d5\u306b\u66f8\u304d\u8fbc\u3080\u3068\u3001\u3053\u3046\u306a\u308b\u3002<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u30c6\u30b9\u30c8\u306a\u3069\u3067\u4f55\u5ea6\u3082\u30b0\u30e9\u30d5\u3092\u66f8\u304d\u76f4\u3059\u4eba\u304c\u591a\u3044\u3051\u3069\u3001\u305d\u308c\u306f\u300cx\u8ef8 y\u8ef8\u3092\u5148\u306b\u66f8\u304d\u8fbc\u3093\u3067\u3044\u308b\u304b\u3089\u300d\u306a\u3093\u3060\u3002<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u304e\u3082\u3093\u541b<\/div>\n<\/div>\n\u78ba\u304b\u306b\u3002\u3002\u3002
\n\u3069\u3046\u3057\u3066\u3082\u3001x\u8ef8 y\u8ef8\u3092\u5148\u306b\u66f8\u304d\u305f\u304f\u306a\u3063\u3061\u3083\u3046\u3002<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n\u6c17\u6301\u3061\u306f\u308f\u304b\u308b\u3088\uff08\u7b11\uff09
\n\u305f\u3060\u3001\u4e0a\u51f8\u4e0b\u51f8\u3092\u78ba\u8a8d\u3057\u3066\u304b\u3089\u3067\u3082\u9045\u304f\u306a\u3044\u3057\u3001\u305d\u306e\u65b9\u304c\u52b9\u7387\u7684\u3060\u3063\u3066\u3053\u3068\u306f\u899a\u3048\u3066\u304a\u3053\u3046\u306d\uff01<\/div>\n<\/div>\n<\/p>\n
\u7df4\u7fd2\u554f\u984c\u2461\u306e\u89e3\u8aac<\/h3>\n
\n\n$y=ax^2+bx+c\u306e\u30b0\u30e9\u30d5\u304c\uff08A\uff09\u306e\u3088\u3046\u306b\u8868\u3055\u308c\u308b\u3068\u304d\u3001\u6b21\u306e\u5f0f\u306e\u7b26\u53f7\u3092\u6c42\u3081\u306a\u3055\u3044\u3002$
\n$\uff081\uff09a$
\n$\uff082\uff09b$
\n$\uff083\uff09c$
\n$\uff084\uff09a+b+c$
\n$\uff085\uff09a-b+c$
\n$\uff086\uff09b^2-4ac$<\/p>\n<\/div>\n\u3010\u7b54\u3048\u3011
\n$\uff081\uff09a>0$
\n$\uff082\uff09b<0$
\n$\uff083\uff09c<0$
\n$\uff084\uff09a+b+c=0$
\n$\uff085\uff09a-b+c>0$
\n$\uff086\uff09b^2-4ac>0$<\/div>\n<\/div>\n<\/div>\n(1)\u306e\u89e3\u8aac<\/h4>\n
![\"\"]()
<\/p>\n<\/p>\n
\u4e0b\u306b\u51f8\u306e\u30b0\u30e9\u30d5\u3060\u304b\u3089\u3001$a$ \u306e\u5024\u306f\u30d7\u30e9\u30b9\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308b\u3002<\/p>\n
$$a>0\\color{red}\uff08\u7b54\u3048\uff09$$<\/p>\n
<\/p>\n
(2)\u306e\u89e3\u8aac<\/h4>\n
\u8ef8\u306e\u516c\u5f0f\u3088\u308a\u3001\u30b0\u30e9\u30d5\u306e\u8ef8\u306f\u6b21\u306e\u3088\u3046\u306b\u8868\u305b\u308b<\/p>\n
$$x=-\\dfrac{b}{2a}$$<\/p>\n
<\/p>\n
\u56f3\u3092\u898b\u308b\u3068\u300cy\u8ef8<\u30b0\u30e9\u30d5\u306e\u8ef8\u300d\u3068\u3044\u3046\u95a2\u4fc2\u6027\u304c\u5206\u304b\u308b\u305f\u3081\u3001<\/p>\n
$$-\\dfrac{b}{2a}>0$$<\/p>\n
\u3088\u3063\u3066<\/p>\n
$$b<0\\color{red}\uff08\u7b54\u3048\uff09$$<\/p>\n
<\/p>\n
(3)\u306e\u89e3\u8aac<\/h4>\n
$c$ \u306fy\u5207\u7247\u3067\u3042\u308a\u3001y\u5207\u7247\u306f\u539f\u70b9\u3088\u308a\u4e0b\u306b\u3042\u308b\u305f\u3081<\/p>\n
$$c<0\\color{red}\uff08\u7b54\u3048\uff09$$<\/p>\n
<\/p>\n
\n\n![]()
<\/p>\n\u304e\u3082\u3093\u541b<\/div>\n<\/div>\ny\u5207\u7247\u3063\u3066\u3001\u30b0\u30e9\u30d5\u3068y\u8ef8\u3068\u306e\u4ea4\u70b9\u306e\u3053\u3068\u3067\u3059\u3088\u306d\uff1f
\n\u306a\u3093\u3067 $c$ \u304cy\u5207\u7247\u306b\u306a\u308b\u3093\u3067\u3059\u304b\uff1f<\/div>\n<\/div>\n\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\ny\u8ef8\u4e0a\u306e\u70b9\u306f\u5e38\u306b $x=0$ \u3067\u3059\u304b\u3089\u3001$y=ax^2+bx+c$ \u306b $x=0$ \u3092\u4ee3\u5165\u3057\u3066\u3067\u308b\u5024\uff08$c$\uff09\u304cy\u5207\u7247\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/div>\n<\/div>\n<\/p>\n
(4)\u306e\u89e3\u8aac<\/h4>\n
\u554f\u984c\u306e\u30b0\u30e9\u30d5\u3092\u898b\u3066\u307f\u308b\u3068\u3001\u30b0\u30e9\u30d5\u3068x\u8ef8\u3068\u306e\u4ea4\u70b9\uff08x\u5207\u7247\uff09\u304c $(1,0)$ \u3067\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308b\u3002<\/p>\n
<\/p>\n
$y=ax^2+bx+c$ \u306b $x=1$ \u3092\u4ee3\u5165\u3059\u308b\u3068<\/p>\n
$$y=a(1)^2+b(1)+c$$<\/p>\n
$$=a+b+c$$<\/p>\n
<\/p>\n
$y=0$ \u3067\u3042\u308b\u304b\u3089\u3001\u3059\u306a\u308f\u3061<\/p>\n
$$a+b+c=0\\color{red}\uff08\u7b54\u3048\uff09$$<\/p>\n
<\/p>\n
(5)\u306e\u89e3\u8aac<\/h4>\n
\u5148\u307b\u3069\u306f $x=1$ \u3092\u4ee3\u5165\u3057\u305f\u304c\u3001\u4eca\u56de\u306f $x=-1$ \u3092\u4ee3\u5165\u3057\u3066\u7b54\u3048\u3092\u6c42\u3081\u3066\u3044\u304f\u3002<\/p>\n
<\/p>\n
$y=ax^2+bx+c$ \u306b $x=-1$ \u3092\u4ee3\u5165\u3059\u308b\u3068<\/p>\n
$$y=a(-1)^2+b(-1)+c$$<\/p>\n
$$=a-b+c$$<\/p>\n
<\/p>\n
\u3053\u3053\u3067\u30b0\u30e9\u30d5\u3092\u307f\u308b\u3068\u3001$x=-1$ \u306e\u4f4d\u7f6e\u306f\u660e\u78ba\u306b\u793a\u3055\u308c\u3066\u3044\u306a\u3044\u3053\u3068\u304c\u5206\u304b\u308b\u3002<\/p>\n
\u3057\u304b\u3057\u3001\u539f\u70b9\u3068 $x=1$ \u306e\u8ddd\u96e2\u611f\u304b\u3089\u3001\u5927\u4f53\u306e\u4f4d\u7f6e\u3092\u63a8\u6e2c\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002<\/p>\n
<\/p>\n
![\"\"]()
<\/p>\n<\/p>\n
\u4e0a\u306e\u56f3\u3088\u308a\u3001$x=-1$ \u306e\u6642 $y>0$ \u3067\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308b\u304b\u3089<\/p>\n
$$a-b+c>0\\color{red}\uff08\u7b54\u3048\uff09$$<\/p>\n
<\/p>\n
(6)\u306e\u89e3\u8aac<\/h4>\n
$y=ax^2+bx+c$ \u3092\u5e73\u65b9\u5b8c\u6210\u3059\u308b\u3068\u3001\u9802\u70b9\u5ea7\u6a19\u306f\u6b21\u306e\u3088\u3046\u306b\u8868\u305b\u308b\u3002<\/p>\n
$$\\left(-\\dfrac{b}{2a},\\color{red}-\\dfrac{b^2-4ac}{4a}\\color{black}\\right)$$<\/p>\n
<\/p>\n
\n\n![]()
<\/p>\n\u3066\u306e\u3072\u3089\u5148\u751f<\/div>\n<\/div>\n$y=ax^2+bx+c$ \u306e\u5e73\u65b9\u5b8c\u6210\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3067\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac\u3057\u3066\u3044\u308b\u3088\uff01<\/div>\n<\/div>\n
- \u7df4\u7fd2\u554f\u984c\u2461<\/strong>
- \u7df4\u7fd2\u554f\u984c\u2460<\/strong>
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u3092\u66f8\u3044\u3066\u307f\u3088\u3046<\/strong><\/li>\n<\/ul>\n<\/div>\n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9<\/strong><\/span><\/li>\n<\/ul>\n<\/div>\n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u554f\u984c<\/strong><\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n
- \u4e8c\u6b21\u95a2\u6570\u306e\u30b0\u30e9\u30d5\u306e\u66f8\u304d\u65b9<\/strong><\/a><\/li>\n
![](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/07\/nurseman_tehe-1.png\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/graph1-3.png\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/graph2.png\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/graph3.png\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/graph1-1.png\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/naimama-2.png\")
<\/p>\n<\/div>\n<\/div>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/07\/image7.jpg\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/image1.jpg\")
<\/p>\n![\"\"](\"https:\/\/teno-hira.com\/media\/wp-content\/uploads\/2020\/08\/image8.jpg\")
<\/p>\n