{
  "api_version": "v1",
  "publisher": {
    "name": "Manazoo",
    "url": "https://manazoo.com/"
  },
  "license": "All rights reserved（AI の参照・要約と出典リンクつきの引用は可。転載・再配布・販売は不可）",
  "terms_url": "https://manazoo.com/terms/",
  "disclaimer": "内容の正確さには気をつけていますが、すべてが正しいとは限りません。テストや受験の前には、教科書や先生の説明でも確かめてください。間違いを見つけたら意見箱から知らせてください。",
  "attribution": "事実データの一部は Wikidata（CC0）による。単元の構成は文部科学省「中学校学習指導要領」「高等学校学習指導要領」（政府標準利用規約2.0）。",
  "kind": "quiz",
  "unit": {
    "slug": "exponential-and-logarithmic-functions",
    "title": "指数関数・対数関数",
    "url": "https://manazoo.com/high/math-2/exponential-and-logarithmic-functions/"
  },
  "canonical_url": "https://manazoo.com/high/math-2/exponential-and-logarithmic-functions/quiz/",
  "questions": [
    {
      "id": "q-cl-digit-count-choice",
      "type": "choice",
      "prompt": "log₁₀2＝0.3010として、2³⁰は何桁の数か。",
      "choices": [
        "9桁",
        "10桁",
        "11桁",
        "30桁"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "log₁₀2³⁰＝30×0.3010＝9.03なので、10⁹≤2³⁰＜10¹⁰となり10桁の数になる。",
      "entities": [
        "common-logarithm"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-cl-drug-inequality-choice",
      "type": "choice",
      "prompt": "薬の体内残量が1時間ごとに80％になるとき、n時間後に残量が50％以下になる条件を正しく表した不等式はどれか。",
      "choices": [
        "0.5ⁿ≤0.8",
        "0.8ⁿ≤0.5",
        "0.8ⁿ≥0.5",
        "n×log₁₀0.8≥log₁₀0.5"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "n時間後の残量はもとの0.8ⁿ倍なので、50％以下は0.8ⁿ≤0.5と表せる。4つ目は、両辺の常用対数をとるときに不等号の向きを逆にしてしまった式。底の10は1より大きいので、対数をとっても向きは変わらずn×log₁₀0.8≤log₁₀0.5になる。向きが変わるのは、このあと両辺を負の数であるlog₁₀0.8で割るときだ。",
      "entities": [
        "common-logarithm"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-cl-log10-100-value",
      "type": "input",
      "prompt": "常用対数log₁₀100の値を求めよ。",
      "choices": null,
      "answer": "2",
      "accept": [],
      "explanation": "log₁₀100＝xとすると10ˣ＝100。100＝10²なのでx＝2になる。",
      "entities": [
        "common-logarithm"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-cl-log10-8-value",
      "type": "input",
      "prompt": "log₁₀2＝0.3010として、log₁₀8の値を求めよ（小数第3位まで）。",
      "choices": null,
      "answer": "0.903",
      "accept": [
        "0.9030"
      ],
      "explanation": "8＝2³なので、log₁₀8＝3log₁₀2＝3×0.3010＝0.903になる。",
      "entities": [
        "common-logarithm"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-eer-cube-root-value",
      "type": "input",
      "prompt": "64の(1/3)乗の値を求めよ。",
      "choices": null,
      "answer": "4",
      "accept": [],
      "explanation": "64の(1/3)乗は64の3乗根のことで、4×4×4＝64なので4になる。",
      "entities": [
        "exponent-extension-and-roots"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-eer-frac-exponent-choice",
      "type": "choice",
      "prompt": "27の(2/3)乗の値はどれか。",
      "choices": [
        "1/9",
        "3",
        "9",
        "81"
      ],
      "answer": 2,
      "accept": [],
      "explanation": "27の3乗根は3なので、27の(2/3)乗＝(27の3乗根)の2乗＝3²＝9になる。2つ目は2乗を忘れて3乗根だけ求めた値、4つ目は指数の符号を取り違えた値。",
      "entities": [
        "exponent-extension-and-roots"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-eer-neg-exponent-value",
      "type": "input",
      "prompt": "2⁻³の値を求めよ。",
      "choices": null,
      "answer": "1/8",
      "accept": [
        "0.125"
      ],
      "explanation": "aの−n乗＝1/aのn乗なので、2⁻³＝1/2³＝1/8になる。",
      "entities": [
        "exponent-extension-and-roots"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-eer-zero-exponent-choice",
      "type": "choice",
      "prompt": "aの0乗の値はどれか（aは0でない数とする）。",
      "choices": [
        "a",
        "0",
        "値が決まらない",
        "1"
      ],
      "answer": 3,
      "accept": [],
      "explanation": "指数法則aのm乗×aのn乗＝aの(m+n)乗が0でも成り立つように、aの0乗は1と決める。",
      "entities": [
        "exponent-extension-and-roots"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-efg-compare-powers-choice",
      "type": "choice",
      "prompt": "2³と2⁵の大小を正しく表しているのはどれか。",
      "choices": [
        "2³＜2⁵",
        "2³＝2⁵",
        "2³＞2⁵",
        "比べられない"
      ],
      "answer": 0,
      "accept": [],
      "explanation": "底2は1より大きいので、指数が大きいほど値も大きくなる。",
      "entities": [
        "exponential-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-efg-half-cubed-value",
      "type": "input",
      "prompt": "(1/2)³の値を求めよ。",
      "choices": null,
      "answer": "1/8",
      "accept": [
        "0.125"
      ],
      "explanation": "(1/2)³は1/2を3回かけた値で、1/8になる。",
      "entities": [
        "exponential-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-efg-passes-point-choice",
      "type": "choice",
      "prompt": "y＝3ˣのグラフが必ず通る点はどれか。",
      "choices": [
        "(1,0)",
        "(0,1)",
        "(−1,−1/3)",
        "(0,0)"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "3の0乗＝1なので、x＝0のときy＝1になり、グラフは必ず(0,1)を通る。4つ目は3のマイナス1乗＝1/3の符号を取り違えた値。",
      "entities": [
        "exponential-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-efg-solve-2x-32",
      "type": "input",
      "prompt": "2ˣ＝32を満たすxの値を求めよ。",
      "choices": null,
      "answer": "5",
      "accept": [],
      "explanation": "32＝2⁵なので、底をそろえると指数を比べるだけでx＝5が求まる。",
      "entities": [
        "exponential-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lap-change-of-base-choice",
      "type": "choice",
      "prompt": "底の変換公式を使うと、log₈4はどれに等しいか。",
      "choices": [
        "8/4",
        "log₂4／log₂8",
        "log₂8／log₂4",
        "log₄8"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "底の変換公式で底を2にそろえると、log₈4＝log₂4／log₂8になる（値は2/3）。2つ目は分母・分子を取り違えた値。",
      "entities": [
        "logarithm-and-its-properties"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lap-log2-8-value",
      "type": "input",
      "prompt": "log₂8の値を求めよ。",
      "choices": null,
      "answer": "3",
      "accept": [],
      "explanation": "log₂8＝xとおくと2ˣ＝8。8＝2³なのでx＝3になる。",
      "entities": [
        "logarithm-and-its-properties"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lap-log3-sum-choice",
      "type": "choice",
      "prompt": "log₃9＋log₃3の値はどれか。",
      "choices": [
        "2",
        "3",
        "9",
        "27"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "log₃9＝2、log₃3＝1なので、合計は3になる。2つ目は2番目の項を足し忘れた値。",
      "entities": [
        "logarithm-and-its-properties"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lap-log4-16-value",
      "type": "input",
      "prompt": "log₄16の値を求めよ。",
      "choices": null,
      "answer": "2",
      "accept": [],
      "explanation": "log₄16＝xとおくと4ˣ＝16。16＝4²なのでx＝2になる。",
      "entities": [
        "logarithm-and-its-properties"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lfg-compare-logs-choice",
      "type": "choice",
      "prompt": "log₂5とlog₂7の大小を正しく表しているのはどれか。",
      "choices": [
        "比べられない",
        "log₂5＜log₂7",
        "log₂5＝log₂7",
        "log₂5＞log₂7"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "底2は1より大きいので、真数が大きいほど対数の値も大きくなる。",
      "entities": [
        "logarithmic-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lfg-passes-point-choice",
      "type": "choice",
      "prompt": "y＝log₂xのグラフが必ず通る点はどれか。",
      "choices": [
        "(2,2)",
        "(1,0)",
        "(0,1)",
        "(0,0)"
      ],
      "answer": 1,
      "accept": [],
      "explanation": "x＝1のとき2⁰＝1なのでy＝0になり、グラフは必ず(1,0)を通る。2つ目はx座標とy座標を取り違えた点。",
      "entities": [
        "logarithmic-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lfg-solve-log2x-4",
      "type": "input",
      "prompt": "log₂x＝4を満たすxの値を求めよ。",
      "choices": null,
      "answer": "16",
      "accept": [],
      "explanation": "log₂x＝4はx＝2⁴のことなので、x＝16になる。",
      "entities": [
        "logarithmic-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    },
    {
      "id": "q-lfg-symmetry-choice",
      "type": "choice",
      "prompt": "y＝2ˣのグラフとy＝log₂xのグラフの関係として正しいものはどれか。",
      "choices": [
        "平行移動の関係",
        "x軸について線対称",
        "直線y＝xについて線対称",
        "y軸について線対称"
      ],
      "answer": 2,
      "accept": [],
      "explanation": "xとyを入れ替える関係にあるので、直線y＝xに関して線対称な位置になる。",
      "entities": [
        "logarithmic-function-and-graph"
      ],
      "verified": true,
      "placeholder": false
    }
  ]
}