Translation guide
The mathematical concept of a logarithm is expressed in Japanese using the term 対数 (taisū). This entry covers how to talk about logarithms in various contexts, from basic definitions to common phrases and notation.
対数
logarithm
Referring to the logarithm function or value in general
The standard mathematical term for 'logarithm'. Used in all formal and technical contexts.
対数は指数の逆演算です。
Logarithms are the inverse operation of exponentiation.
常用対数は底が10の対数です。
Common logarithms are logarithms with base 10.
Distinguishing between common, natural, and binary logarithms
Common logarithm (base 10). Often used in science and engineering.
pHは水素イオン濃度の常用対数で表されます。
pH is expressed as the common logarithm of the hydrogen ion concentration.
Binary logarithm (base 2). Common in computer science.
アルゴリズムの計算量は二進対数で表されることが多い。
The computational complexity of algorithms is often expressed in binary logarithms.
Describing something that follows a logarithmic pattern
Logarithmic scale (on a graph or instrument).
このグラフの縦軸は対数目盛です。
The vertical axis of this graph is a logarithmic scale.
Adjectival form meaning 'logarithmic'. Used to describe growth, decay, etc.
Referring to the function y = log(x) or its curve
Logarithmic function. Standard term in mathematics.
対数関数のグラフはx軸に漸近します。
The graph of a logarithmic function approaches the x-axis asymptotically.
Logarithmic curve. Emphasizes the shape of the graph.
このデータは対数曲線によく当てはまる。
This data fits a logarithmic curve well.
Talking about a mathematical expression containing a logarithm
Logarithmic expression. Used in algebra contexts.
この対数式を簡単にしてください。
Please simplify this logarithmic expression.
Logarithmic equation. An equation involving logarithms.
対数方程式を解くには真数条件に注意する。
When solving logarithmic equations, pay attention to the domain of the argument.
Referring to historical or manual computation aids
Logarithm table. Used before calculators were common.
昔は対数表を使って計算していた。
In the past, people used logarithm tables for calculations.
Slide rule. A mechanical analog computer based on logarithms.
When reading 'log₂ 8 = 3' aloud, say 「ログにの8は3」 (rogu ni no hachi wa san). The base is indicated with に (ni) after ログ. For natural log, 'ln' is read as エルエヌ (eru enu) or 自然対数 (shizen taisū).
Natural logarithm (base e). Widely used in mathematics and physics.
自然対数の底はネイピア数です。
The base of the natural logarithm is Napier's constant.
Bacterial growth increases logarithmically.
計算尺は対数の原理を利用している。
The slide rule uses the principle of logarithms.