{"id":6635,"date":"2025-12-24T17:21:06","date_gmt":"2025-12-24T08:21:06","guid":{"rendered":"https:\/\/math-travel.com\/?p=6635"},"modified":"2026-02-11T17:23:48","modified_gmt":"2026-02-11T08:23:48","slug":"taisuu-futoushiki","status":"publish","type":"post","link":"https:\/\/math-travel.jp\/math-2\/taisuu-futoushiki\/","title":{"rendered":"\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3068\u6ce8\u610f\u70b9\u30fc\u771f\u6570\u6761\u4ef6\u3068\u5e95\u306e\u5024\u306b\u3088\u308b5\u3064\u306e\u30d1\u30bf\u30fc\u30f3\u3092\u89e3\u8aac"},"content":{"rendered":"\n
\u300c\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u304c\u5206\u304b\u3089\u306a\u3044\u300d<\/p>\n\n\n\n
\u300c\u5e95\u306b\u6587\u5b57\u304c\u3042\u308b\u3068\u304d\u306f\u3069\u3046\u3059\u308b\u306e\uff1f\u300d<\/p>\n<\/div><\/div>\n\n\n\n
\u5bfe\u6570\u306e\u4e0d\u7b49\u5f0f\u304c\u89e3\u3051\u306a\u3044\u65b9\u306f\u5fc5\u898b\u3067\u3059\uff01<\/span><\/p>\n\n\n\n \u4eca\u56de\u306f\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306b\u95a2\u3059\u308b\u3053\u3093\u306a\u60a9\u307f\u3092\u89e3\u6c7a\u3057\u307e\u3059\u3002<\/p>\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u3067\u983b\u51fa\u306e\u554f\u984c\u30925\u3064\u30d4\u30c3\u30af\u30a2\u30c3\u30d7\u3057\u3066\u3001\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3092\u89e3\u8aac\u3057\u307e\u3059\u3002<\/span><\/p>\n\n\n\n 5\u3064\u306e\u983b\u51fa\u554f\u984c\u3092\u9806\u756a\u306b\u89e3\u8aac\u3057\u3066\u3044\u304f\u306e\u3067\u3001\u6700\u5f8c\u307e\u3067\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n\n\n \u6c17\u306b\u306a\u308b\u898b\u51fa\u3057\u3092\u30af\u30ea\u30c3\u30af\u3057\u3066\u3001 \u5bfe\u6570log\u3092\u542b\u3080\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u95a2\u6570\u3092\u5bfe\u6570\u95a2\u6570<\/span>\u3068\u3044\u3044\u307e\u3059\u3002<\/p>\n\n\n\n \\(a>0,a\u22601,x>0\\)\u306e\u3068\u304d\u3001<\/p>\n\n\n\n \\[y=log_{a}x\\]<\/p>\n<\/div><\/div>\n\n\n\n \\(a\\)\u306f\u6b63\u306e\u6570\u3060\u3051\u308c\u3069\u30011\u306b\u306f\u7d76\u5bfe\u306b\u306a\u3089\u306a\u3044\u306e\u3082\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002<\/p>\n\n\n\n \u5bfe\u6570\u95a2\u6570\u306f\u3001\u5e95\\(a\\)\u306e\u5024\u306b\u3088\u3063\u3066\u30b0\u30e9\u30d5\u306e\u5f62\u304c\u7570\u306a\u308a\u307e\u3059\u3002<\/span><\/p>\n\n\n\n \\(a>1\\)\u306e\u3068\u304d\u306f\u3001\u53f3\u4e0a\u304c\u308a\u306e\u30b0\u30e9\u30d5<\/p>\n\n\n\n \\(0<a<1\\)\u306e\u3068\u304d\u306f\u3001\u53f3\u4e0b\u304c\u308a\u306e\u30b0\u30e9\u30d5<\/p>\n<\/div><\/div>\n\n\n \u30b0\u30e9\u30d5\u306e\u5f62\u304c\u5206\u304b\u308b\u3068\u4e0d\u7b49\u5f0f\u3082\u89e3\u304d\u3084\u3059\u3044\u3088<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5bfe\u6570\u95a2\u6570\u3092\u542b\u3080\u4e0d\u7b49\u5f0f\u3092\u5bfe\u6570\u4e0d\u7b49\u5f0f<\/span>\u3068\u3044\u3044\u307e\u3059\u3002<\/p>\n\n\n\n \\[log_{2}x>3\\]<\/p>\n\n\n\n \\[2log_{3}(2-x)<log_{3}(x+4)\\]<\/p>\n<\/div><\/div>\n\n\n\n \u3053\u306e\u4e0d\u7b49\u5f0f\u3092\u6e80\u305f\u3059\\(x\\)\u306e\u5909\u57df\u3092\u6c42\u3081\u308b\u306e\u304c\u3001\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u554f\u984c\u3067\u3059\u3002<\/p>\n\n\n\n \u3088\u304f\u51fa\u984c\u3055\u308c\u308b5\u554f\u3092\u7528\u610f\u3057\u305f\u306e\u3067\u3001\u89e3\u304d\u65b9\u3092\u78ba\u8a8d\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \u307e\u305f\u3001\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306b\u5408\u308f\u305b\u3066\u3001\u5bfe\u6570\u65b9\u7a0b\u5f0f\u3082\u78ba\u8a8d\u3057\u3066\u304a\u304f\u3068\u30b9\u30e0\u30fc\u30ba\u7406\u89e3\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n >>\u5bfe\u6570\u65b9\u7a0b\u5f0f\u306e\u89e3\u304d\u65b9\uff01\u771f\u6570\u6761\u4ef6\u3068\u5e95\u306e\u5024\u306b\u6ce8\u610f\uff01<\/p>\n\n\n \u3069\u3063\u3061\u3082\u82e6\u624b\u306a\u306e\u3067\u78ba\u8a8d\u3057\u307e\u3059\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u304f\u3068\u304d\u306f\u3001\u771f\u6570\u6761\u4ef6\u3068\u5e95\\(a\\)\u306e\u5024\u306b\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002<\/span><\/p>\n\n\n\n \u771f\u6570\u306b\u306f\u300c\u771f\u6570\u306f\u5e38\u306b\u6b63\u306e\u5024\u3067\u3042\u308b\u300d<\/span>\u3068\u3044\u3046\u6761\u4ef6\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n (y=log_{a}x)\u306b\u304a\u3044\u3066\u3001\u771f\u6570(x)\u306f\u6b63\u306e\u6570\u3067\u3042\u308b\u3002<\/p>\n<\/div><\/div>\n\n\n \u771f\u6570\u6761\u4ef6\u3068\u3042\u308f\u305b\u3066\u3001\u5e95\\(a\\)\u306e\u5024\u306b\u3082\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \\(a>0.a\u22601,x>0\\)\u306b\u304a\u3044\u3066\u3001<\/p>\n\n\n\n \\(a>1\\)\u306a\u3089\u3070\u3001\\(y=log_{a}x\\)\u306f\u5897\u52a0\u95a2\u6570\u306a\u306e\u3067<\/p>\n\n\n\n \\[log_{a}m<log_{a}n \\Leftrightarrow m<n\\]<\/p>\n\n\n\n \\(0<a<1\\)\u306a\u3089\u3070\u3001\\(y=log_{a}x\\)\u306f\u6e1b\u5c11\u95a2\u6570\u306a\u306e\u3067<\/p>\n\n\n\n \\[log_{a}m<log_{a}n \\Leftrightarrow m>n\\]<\/p>\n<\/div><\/div>\n\n\n\n \\(a>1\\)\u306e\u3068\u304d\u306f\u3001\u30b0\u30e9\u30d5\u304c\u53f3\u80a9\u4e0a\u304c\u308a\u306a\u306e\u3067<\/p>\n\n\n\n \\(log_{a}m<log_{a}n\\)\u306e\u3068\u304d\u3001\\(m<n\\)<\/p>\n\n\n\n \u304c\u6210\u308a\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n \\(a>1\\)\u306e\u3068\u304d\u3001<\/p>\n\n\n\n \\[alog_{a}m<log_{a}n \\Leftrightarrow m<n\\]<\/p>\n<\/div><\/div>\n\n\n\n \u3057\u304b\u3057\u3001\\(0<a<1\\)\u306e\u3068\u304d\u306f\u30b0\u30e9\u30d5\u306e\u53f3\u80a9\u4e0b\u304c\u308a\u306b\u306a\u308b\u306e\u3067\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u304c\u9006<\/span>\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n \\(0<a<1\\)\u306e\u3068\u304d\u3001<\/p>\n\n\n\n \\[log_{a}m<log_{a}n \\Leftrightarrow m>n\\]<\/p>\n<\/div><\/div>\n\n\n\n \u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u305f\u3089\u3001\\(a\\)\u306e\u5024\u3068\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u3092\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3057\u3087\u3046\u3002<\/span><\/p>\n\n\n\n \u304b\u306a\u308a\u91cd\u8981\u306a\u3053\u3068\u3092\u8a00\u3044\u307e\u3057\u305f\u3002<\/span><\/p>\n\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u304c\u82e6\u624b\u306a\u65b9\u306f\u3057\u3063\u304b\u308a\u8aad\u3093\u3067\u304f\u3060\u3055\u3044\u3002<\/span><\/p>\n\n\n \u4e0d\u7b49\u53f7\u306e\u5411\u304d\u3092\u9593\u9055\u3048\u308b\u3053\u3068\u304c\u307b\u3093\u3068\u306b\u591a\u3044\u3088<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3092\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/span><\/p>\n\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u3067\u306f\u4ee5\u4e0b\u306e5\u30d1\u30bf\u30fc\u30f3\u304c\u3088\u304f\u51fa\u984c\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n \u6307\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3092\u89e3\u8aac\u3057\u3066\u3044\u304f\u3088\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5e95\u304c1\u3088\u308a\u5927\u304d\u3044\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306f\u30b7\u30f3\u30d7\u30eb\u3067\u3059\u3002<\/p>\n\n\n\n \u6b21\u306e\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (1)\\(log_{3}x>log_{3}7\\)<\/p>\n\n\n\n (2)\\(log_{2}x\u22663\\)<\/p>\n<\/div><\/div>\n\n\n\n (1)\u306f\u4e21\u8fba\u306e\u5e95\u306e\u5024\u304c\u540c\u3058\u306a\u306e\u3067\u3001\u3053\u306e\u307e\u307e\u771f\u6570\u3092\u6bd4\u8f03\u3057\u307e\u3059\u3002<\/p>\n\n\n\n \\[log_{3}x>log_{3}7\\]<\/p>\n\n\n\n \u5e953\u306f1\u3088\u308a\u5927\u304d\u3044\u306e\u3067\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306f\u5909\u308f\u308a\u307e\u305b\u3093\u3002<\/p>\n\n\n\n \\[x>7\\]<\/p>\n\n\n\n (2)\u306f\u53f3\u8fba\u3092\u5bfe\u6570\u8868\u8a18\u306b\u3059\u308b\u3053\u3068\u3067\u3001\u4e0d\u7b49\u5f0f\u3092\u89e3\u304d\u307e\u3059\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u5e952\u306f1\u3088\u308a\u5927\u304d\u3044\u306e\u3067\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u3092\u5909\u3048\u305a\u306b\u6bd4\u8f03\u3057\u307e\u3059\u3002<\/p>\n\n\n\n \\[x\u22668\\]<\/p>\n\n\n\n \u771f\u6570\u6761\u4ef6\u304b\u3089\u3001\\(x>0\\)\u306a\u306e\u3067<\/p>\n\n\n\n \\[0<x\u22668\\]<\/p>\n\n\n\n \u3053\u306e\u30d1\u30bf\u30fc\u30f3\u306f\u8d85\u57fa\u672c\u306e\u554f\u984c\u306a\u306e\u3067\u3001\u5fc5\u305a\u89e3\u3051\u308b\u3088\u3046\u306b\u3057\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n \u3053\u308c\u306a\u3089\u5927\u4e08\u592b\u305d\u3046\u3067\u3059\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u5834\u5408\u306f\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306b\u6ce8\u610f<\/span>\u3057\u3066\u4e0b\u3055\u3044\u3002<\/p>\n\n\n\n \u6b21\u306e\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (1)\\(\\displaystyle log_{\\frac{1}{2}}x<log_{\\frac{1}{2}}3\\)<\/p>\n\n\n\n (2)\\(\\displaystyle log_{\\frac{1}{3}}x\u2267-2\\)<\/p>\n<\/div><\/div>\n\n\n\n (1)\u306f\u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u306e\u3067\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u3092\u9006\u306b\u3057\u3066\u771f\u6570\u3092\u6bd4\u8f03\u3057\u307e\u3059\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306b\u3088\u308b\u30df\u30b9\u304c\u591a\u767a\u3059\u308b\u306e\u3067\u3001\u610f\u8b58\u3057\u3066\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \u554f(2)\u3067\u306f\u3001\u4e21\u8fba\u3092\u5e95\\(\\displaystyle \\frac{1}{3}\\)\u306e\u5bfe\u6570\u306b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u306e\u3067\u3001<\/p>\n\n\n\n \\[x\u22669\\]<\/p>\n\n\n\n \u771f\u6570\u6761\u4ef6\u3088\u308a\u3001\\(x>0\\)\u306a\u306e\u3067<\/p>\n\n\n\n \u6c42\u3081\u308b\u4e0d\u7b49\u5f0f\u306e\u89e3\u306f<\/p>\n\n\n\n \\[0<x\u22669\\]<\/p>\n\n\n \u5e95\u304c\u8ca0\u306e\u6570\u306e\u3068\u304d\u306f\u3069\u3046\u3059\u308b\u3093\u3067\u3059\u304b\uff1f<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n \u5e95\u304c\u30de\u30a4\u30ca\u30b9\u306b\u306a\u308b\u3053\u3068\u306f\u306a\u3044\u306e\u3067\u3001\u305d\u308c\u3082\u899a\u3048\u3066\u304a\u3053\u3046<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u4e21\u8fba\u306e\u5e95\u304c\u7570\u306a\u308b\u3068\u304d\u306f\u3001\u5e95\u306e\u5909\u63db\u516c\u5f0f<\/span>\u3092\u7528\u3044\u3066\u5e95\u3092\u305d\u308d\u3048\u307e\u3059\u3002<\/p>\n\n\n\n \u6b21\u306e\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n \\[\\displaystyle log_{2}x<log_{4}3\\]<\/p>\n<\/div><\/div>\n\n\n\n \u307e\u305a\u771f\u6570\u6761\u4ef6\u3088\u308a\u3001<\/p>\n\n\n\n \\[x>0 \\cdots \u2460\\]<\/p>\n\n\n\n \u4e0e\u3048\u3089\u308c\u305f\u4e0d\u7b49\u5f0f\u3067\u306f\u4e21\u8fba\u306e\u5e95\u304c\u7570\u306a\u308b\u306e\u3067\u3001\u5e95\u306e\u5909\u63db\u516c\u5f0f\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \\(a,b,c>0\u3001a,c\u22601\\)\u306e\u3068\u304d<\/p>\n\n\n\n \\[\\displaystyle log_{a}b=\\frac{log_{c}b}{log_{c}a}\\]<\/p>\n<\/div><\/div>\n\n\n\n \u4e21\u8fba\u306e\u5e95\u304c2\u306b\u306a\u308b\u3088\u3046\u306b\u5909\u63db\u3057\u307e\u3059\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u3044\u304f\u3068\u3001<\/p>\n\n\n\n \\begin{eqnarray} \u5e95\u304c1\u3088\u308a\u5927\u304d\u3044\u306e\u3067\u3001<\/p>\n\n\n\n \\[x^{2}<3 \\cdots \u2461\\]<\/p>\n\n\n\n \u2460,\u2461\u3088\u308a\u3001<\/p>\n\n\n\n \\[0<x<\\sqrt{3}\\]<\/p>\n\n\n\n \u5e95\u306e\u5909\u63db\u516c\u5f0f\u306f\u30b9\u30e0\u30fc\u30ba\u306b\u4f7f\u3048\u308b\u3088\u3046\u306b\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n \u5e95\u3092\u305d\u308d\u3048\u308b\u5de5\u592b\u304c\u5fc5\u8981\u306a\u3093\u3067\u3059\u306d\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5e95\u304c\u5206\u6570\u3060\u3068\u3057\u3066\u3082\u30011\u3068\u306e\u5927\u5c0f\u95a2\u4fc2\u306b\u3055\u3048\u6ce8\u610f\u3059\u308c\u3070\u7c21\u5358\u306a\u554f\u984c\u3067\u3059\u3002<\/p>\n\n\n\n \u6b21\u306e\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (1)\\(\\displaystyle log_{\\frac{7}{10}}x<log_{\\frac{7}{10}}3\\)<\/p>\n\n\n\n (2)\\(\\displaystyle log_{\\frac{5}{2}}x\u2266log_{\\frac{5}{2}}7\\)<\/p>\n<\/div><\/div>\n\n\n\n (1)\u306f\u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u306e\u3067\u3001<\/p>\n\n\n\n \\[\\displaystyle log_{\\frac{7}{10}}x<log_{\\frac{7}{10}}3\\]<\/p>\n\n\n\n \u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306b\u6ce8\u610f\u3057\u3066\u3001<\/p>\n\n\n\n \\[x>3\\]<\/p>\n\n\n\n (2)\u306f\u5e95\u304c1\u3088\u308a\u5927\u304d\u3044\u306e\u3067\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306f\u5909\u308f\u308a\u307e\u305b\u3093\u3002<\/p>\n\n\n\n \u771f\u6570\u6761\u4ef6\u3088\u308a\u3001<\/p>\n\n\n\n \\[x>0 \\cdots \u2460\\]<\/p>\n\n\n\n \u4e0e\u3048\u3089\u308c\u305f\u4e0d\u7b49\u53f7\u3092\u89e3\u304f\u3068\u3001<\/p>\n\n\n\n \\[\\displaystyle log_{\\frac{5}{2}}x\u2266log_{\\frac{5}{2}}7\\]<\/p>\n\n\n\n \\[x\u22667 \\cdots \u2461\\]<\/p>\n\n\n\n \u2460,\u2461\u3088\u308a<\/p>\n\n\n\n \\[0<x\u22667\\]<\/p>\n\n\n\n \u5206\u6570\u304c\u3042\u308b\u3068\u4e0d\u5b89\u306b\u306a\u308b\u6c17\u6301\u3061\u306f\u5206\u304b\u308a\u307e\u3059\u304c\u3001\u96e3\u3057\u3044\u554f\u984c\u3067\u306f\u306a\u3044\u306e\u3067\u51b7\u9759\u306b\u5bfe\u51e6\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n \u5e95\u306e\u5024\u306b\u3060\u3051\u6c17\u3092\u4ed8\u3051\u308c\u3070\u89e3\u3051\u308b\u3088\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u5e95\u306b\u6587\u5b57\u3092\u542b\u3080\u3068\u304d\u306f\u3001\u5834\u5408\u5206\u3051<\/span>\u3092\u3057\u3066\u8003\u3048\u307e\u3059\u3002<\/p>\n\n\n\n \u6b21\u306e\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n \\[log_{a}x<log_{a}5\\]<\/p>\n<\/div><\/div>\n\n\n\n \u5e95\\(a\\)\u306e\u5024\u306b\u3088\u3063\u3066\u3001\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u304c\u5909\u308f\u308b\u306e\u3067\u5834\u5408\u5206\u3051\u3057\u3066\u8003\u3048\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \u307e\u305a\u771f\u6570\u6761\u4ef6\u3088\u308a<\/p>\n\n\n\n \\[x>0 \\cdots \u2460\\]<\/p>\n\n\n\n \u5e95\u306e\u6761\u4ef6\u304b\u3089\\(a>0,a\u22601\\)\u306a\u306e\u3067\u3001\u4ee5\u4e0b\u306e2\u3064\u306b\u5834\u5408\u5206\u3051\u3057\u3066\u8003\u3048\u307e\u3059\u3002<\/p>\n\n\n\n (\u2170)(a>1)\u306e\u3068\u304d (\u2170)\\(a>1\\)\u306e\u3068\u304d<\/span><\/p>\n\n\n\n \\[log_{a}x<log_{a}5\\]<\/p>\n\n\n\n \\[x<5\\]<\/p>\n\n\n\n \u2460\u3088\u308a\u3001<\/p>\n\n\n\n \\[0<x<5\\]<\/p>\n\n\n\n (\u2171)\\(0<a<1\\)\u306e\u3068\u304d<\/span><\/p>\n\n\n\n \\[log_{a}x<log_{a}5\\]<\/p>\n\n\n\n \\[x>5\\]<\/p>\n\n\n\n \u3057\u305f\u304c\u3063\u3066\u3001\u4e0d\u7b49\u5f0f\u3092\u89e3\u304f\u3068<\/p>\n\n\n\n \\begin{eqnarray} \u3053\u306e\u3088\u3046\u306b\u3001\u5e95\u3084\u771f\u6570\u306b\u6587\u5b57\u304c\u542b\u307e\u308c\u3066\u3044\u308b\u3068\u304d\u306f\u3001\u81ea\u5206\u3067\u5834\u5408\u5206\u3051\u3092\u3057\u3066\u4e0d\u7b49\u5f0f\u3092\u89e3\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u7df4\u7fd2\u554f\u984c\u306b\u6311\u6226\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \u4ee5\u4e0b\u304c\u4eca\u56de\u306e\u7df4\u7fd2\u554f\u984c\u3067\u3059\u3002<\/p>\n\n\n\n \u6b21\u306e\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (1)\\(\\displaystyle log_{\\frac{1}{3}}(3-2x)\u2266log_{\\frac{1}{3}}x\\)<\/p>\n\n\n\n (2)\\(log_{3}x\u2266log_{9}5\\)<\/p>\n\n\n\n (3)\\(\\displaystyle log_{a}(x-3)\u2266log_{a}5\\)<\/p>\n<\/div><\/div>\n\n\n \u3069\u306e\u30d1\u30bf\u30fc\u30f3\u306e\u554f\u984c\u306a\u306e\u304b\u3092\u8003\u3048\u308b\u3060\u3051\u3067\u3082\u30aa\u30c3\u30b1\u30fc\uff01<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n \u6b21\u306e\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (1)\\(\\displaystyle log_{\\frac{1}{3}}(3-2x)\u2266log_{\\frac{1}{3}}x\\)<\/p>\n<\/div><\/div>\n\n\n\n \u3053\u308c\u306f\u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u554f\u984c\u3067\u3059\u306d\u3002<\/p>\n\n\n\n \u771f\u6570\u306f\u6b63\u3067\u3042\u308b\u306e\u3067\u3001\\(3-2x>0\\)\u304b\u3064\\(x>0\\)<\/p>\n\n\n\n \u3059\u306a\u308f\u3061\u3001\\(\\displaystyle 0<x<\\frac{3}{2} \\cdots \u2460\\)<\/p>\n\n\n\n \u5e95\\(\\displaystyle \\frac{1}{3}\\)\u306f1\u3088\u308a\u5c0f\u3055\u3044\u306e\u3067<\/p>\n\n\n\n \\begin{eqnarray} \u2460,\u2461\u3088\u308a\u3001<\/p>\n\n\n\n \\[0<x\u22661\\]<\/p>\n\n\n\n \u6b21\u306e\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (2)\\(log_{3}x\u2266log_{9}5\\)<\/p>\n<\/div><\/div>\n\n\n\n \u307e\u305a\u306f\u4e21\u8fba\u306e\u5e95\u3092\u305d\u308d\u3048\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u4e21\u8fba\u306e\u5e95\u3092\u5408\u308f\u305b\u308b\u3053\u3068\u304c\u3067\u304d\u305f\u306e\u3067\u3001\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n \\begin{eqnarray} \u5e953\u306f1\u3088\u308a\u5927\u304d\u3044\u306e\u3067\u3001<\/p>\n\n\n\n \\begin{eqnarray} \u771f\u6570\u306f\u6b63\u306a\u306e\u3067\u3001\\(x>0 \\cdots \u2461\\)<\/p>\n\n\n\n \u2460,\u2461\u3088\u308a\u3001<\/p>\n\n\n\n \\[0<x\u2266\\sqrt{5}\\]<\/p>\n\n\n\n \u6b21\u306e\u4e0d\u7b49\u5f0f\u3092\u89e3\u3044\u3066\u307f\u3088\u3046\u3002<\/p>\n\n\n\n (3)\\(\\displaystyle log_{a}(x-3)\u2266log_{a}5\\)<\/p>\n<\/div><\/div>\n\n\n\n \u5e95\u306b\u6587\u5b57\u3092\u542b\u3093\u3067\u3044\u308b\u306e\u3067\u3001\u5834\u5408\u5206\u3051\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n\n\n \u771f\u6570\u306f\u6b63\u306a\u306e\u3067\u3001\\(x>3 \\cdots \u2460\\)<\/p>\n\n\n\n \u5e95\u306e\u6761\u4ef6\u3088\u308a\u3001\\(a>0,a\u22601\\)<\/p>\n\n\n\n (\u2170)a>1\u306e\u3068\u304d<\/p>\n\n\n\n \\begin{eqnarray} \u2460,\u2461\u3088\u308a\u3001<\/p>\n\n\n\n \\[0<x\u22668\\]<\/p>\n\n\n\n (\u2171)0<a<1\u306e\u3068\u304d<\/p>\n\n\n\n \\begin{eqnarray} \u3057\u305f\u304c\u3063\u3066\u3001<\/p>\n\n\n\n \\begin{eqnarray} \u4eca\u56de\u306f\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306b\u3064\u3044\u3066\u307e\u3068\u3081\u307e\u3057\u305f\u3002<\/span><\/p>\n\n\n\n \u5bfe\u6570\u4e0d\u7b49\u5f0f\u306f\u4ee5\u4e0b\u306e2\u3064\u306b\u6ce8\u610f\u3059\u308b\u3053\u3068\u3002<\/p>\n\n\n\n \u5e95\u306e\u5024\u306b\u3088\u3063\u3066\u4e0d\u7b49\u53f7\u306e\u5411\u304d\u306b\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n \\(a>0.a\u22601,x>0\\)\u306b\u304a\u3044\u3066\u3001<\/p>\n\n\n\n \\(a>1\\)\u306a\u3089\u3070\u3001\\(y=log_{a}x\\)\u306f\u5897\u52a0\u95a2\u6570\u306a\u306e\u3067<\/p>\n\n\n\n \\[log_{a}m<log_{a}n \\Leftrightarrow m<n\\]<\/p>\n\n\n\n \\(0<a<1\\)\u306a\u3089\u3070\u3001\\(y=log_{a}x\\)\u306f\u6e1b\u5c11\u95a2\u6570\u306a\u306e\u3067<\/p>\n\n\n\n \\[log_{a}m<log_{a}n \\Leftrightarrow m>n\\]<\/p>\n<\/div><\/div>\n\n\n\n \u4ee5\u4e0b\u306e5\u30d1\u30bf\u30fc\u30f3\u306f\u3088\u304f\u51fa\u984c\u3055\u308c\u308b\u306e\u3067\u3001\u89e3\u304d\u65b9\u306b\u6163\u308c\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n
<\/figure>\n<\/div>\n\n\n\n
\u30b7\u30fc\u30bf<\/span><\/div>
\u305c\u3072\u6700\u5f8c\u307e\u3067\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n<\/span><\/span><\/span><\/div><\/div><\/div><\/div>\n\n\n\u305d\u3082\u305d\u3082\u5bfe\u6570\u95a2\u6570\u3068\u306f\uff1f<\/h2>\n\n\n\n
<\/figure>\n<\/div>\n
<\/figure>\n<\/div>\n<\/div>\n\n\n\n
\u30b7\u30fc\u30bf<\/span><\/div>\u5bfe\u6570\u4e0d\u7b49\u5f0f<\/h2>\n\n\n\n
\u9ad8\u6821\u751f<\/span><\/div>\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3092\u89e3\u304f\u3068\u304d\u306e\u6ce8\u610f\u70b9<\/h2>\n\n\n\n
<\/figure>\n<\/div>\n\n\n
<\/figure>\n<\/div>\n\n\n
<\/figure>\n<\/div>\n\n\n
\u30b7\u30fc\u30bf<\/span><\/div>\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3092\u89e3\u8aac\uff01<\/h2>\n\n\n\n
\n
\u30b7\u30fc\u30bf<\/span><\/div>\u5e95\u304c1\u3088\u308a\u5927\u304d\u3044\u3068\u304d<\/h3>\n\n\n\n
log_{2}x&\u2266&3\\\\
log_{2}x&\u2266&log_{2}8
\\end{eqnarray}<\/p>\n\n\n\n
\u9ad8\u6821\u751f<\/span><\/div>\u5e95\u304c1\u3088\u308a\u5c0f\u3055\u3044\u3068\u304d<\/h3>\n\n\n\n
\\displaystyle log_{\\frac{1}{2}}x&<&log_{\\frac{1}{2}}3\\\\
x&>&3
\\end{eqnarray}<\/p>\n\n\n\n
\\displaystyle log_{\\frac{1}{3}}x&\u2267&-2\\\\
\\displaystyle log_{\\frac{1}{3}}x&\u2267&log_{\\frac{1}{3}}\\left(\\frac{1}{3}\\right)^{-2}\\\\
\\displaystyle log_{\\frac{1}{3}}x&\u2267&log_{\\frac{1}{3}}9\\\\
\\end{eqnarray}<\/p>\n\n\n\n
\u9ad8\u6821\u751f<\/span><\/div>
\u30b7\u30fc\u30bf<\/span><\/div>\u5e95\u304c\u7570\u306a\u308b\u3068\u304d<\/h3>\n\n\n\n
\\displaystyle log_{2}x&<&log_{4}3\\\\
\\displaystyle log_{2}x&<&\\frac{log_{2}3}{log_{2}4}\\\\
\\displaystyle log_{2}x&<&\\frac{log_{2}3}{2}
\\end{eqnarray}<\/p>\n\n\n\n
\\displaystyle 2log_{2}x&<&log_{2}3\\\\
\\displaystyle log_{2}x^{2}&<&log_{2}3\\\\
\\end{eqnarray}<\/p>\n\n\n\n
\u9ad8\u6821\u751f<\/span><\/div>\u5e95\u304c\u5206\u6570\u306e\u3068\u304d<\/h3>\n\n\n\n
\u30b7\u30fc\u30bf<\/span><\/div>\u5e95\u306b\u6587\u5b57\u3092\u542b\u3080\u3068\u304d<\/h3>\n\n\n\n
(\u2171)(0<a<1)\u306e\u3068\u304d<\/p>\n<\/div><\/div>\n\n\n\n
0<x<5&\uff08&a>1\u306e\u3068\u304d\uff09\\\\
x>5&\uff08&0<a<1\u306e\u3068\u304d\uff09
\\end{eqnarray}<\/p>\n\n\n\n\u5bfe\u6570\u4e0d\u7b49\u5f0f\u3010\u7df4\u7fd2\u554f\u984c\u3011<\/h2>\n\n\n
<\/figure>\n<\/div>\n\n\n
\u30b7\u30fc\u30bf<\/span><\/div>\u7df4\u7fd2\u554f\u984c1\u306e\u89e3\u8aac<\/h3>\n\n\n\n
\\displaystyle log_{\\frac{1}{3}}(3-2x)&\u2266&log_{\\frac{1}{3}}x\\\\
3-2x&\u2267&x\\\\
1&\u2267&x\u3000\\cdots \u2461
\\end{eqnarray}<\/p>\n\n\n\n\u7df4\u7fd2\u554f\u984c2\u306e\u89e3\u8aac<\/h3>\n\n\n\n
\\displaystyle log_{3}x&\u2266&\\frac{log_{3}5}{log_{3}9}\\\\
\\displaystyle log_{3}x&\u2266&\\frac{log_{3}5}{2}
\\end{eqnarray}<\/p>\n\n\n\n
\\displaystyle 2log_{3}x&\u2266&log_{3}5\\\\
\\displaystyle log_{3}x^{2}&\u2266&log_{3}5
\\end{eqnarray}<\/p>\n\n\n\n
x^{2}&\u2266&5\\\\
-\\sqrt{5}\u2266&x&\u2266\\sqrt{5}\u3000\\cdots \u2460
\\end{eqnarray}<\/p>\n\n\n\n\u7df4\u7fd2\u554f\u984c3\u306e\u89e3\u8aac<\/h3>\n\n\n\n
\\displaystyle log_{a}(x-3)&\u2266&log_{a}5\\\\
x-3&\u2266&5\\\\
x&\u2266&8\u3000\\cdots \u2461
\\end{eqnarray}<\/p>\n\n\n\n
\\displaystyle log_{a}(x-3)&\u2266&log_{a}5\\\\
x-3&\u2267&5\\\\
x&\u2267&8
\\end{eqnarray}<\/p>\n\n\n\n
0<&x&\u22668\uff08a>1\u306e\u3068\u304d\uff09\\\\
x&\u2267&8\uff080<a<1\u306e\u3068\u304d\uff09
\\end{eqnarray}<\/p>\n\n\n\n\u5bfe\u6570\u4e0d\u7b49\u5f0f\u306e\u89e3\u304d\u65b9\u3000\u307e\u3068\u3081<\/h2>\n\n\n\n
\n