近似

• Reading: きんじ
• Romaji: kinji
• Kanji breakdown: 近 (kin) — near, close; 似 (ji) — to resemble, to be similar
• Pronunciation: /kiɴ.dʑi/

Meaning

Approximation; an estimate or representation that is close to, but not exactly equal to, the true value or form.

A mathematical and scientific term for values, functions, or models that are close to but not identical to the true value. 線形近似 (linear approximation) and テイラー展開 (Taylor expansion) are foundational approximation techniques. In physics, 近似解 (approximate solution) is contrasted with 厳密解 (exact solution). 近似的に (approximately) is used as an adverb. The verb form is 近似する. Distinguished from 概算 (rough estimate) in being more mathematically precise.

Examples

1. 小さな角度の場合、sinθ ≈ θ という近似がよく使われる。 For small angles, the approximation sinθ ≈ θ is commonly used.
2. この積分は解析的に解けないため、数値的近似によって解を求める必要がある。 Since this integral cannot be solved analytically, the solution must be found by numerical approximation.
3. 複雑な非線形システムを解析するために、線形近似モデルがしばしば用いられる。 Linear approximation models are often used to analyse complex non-linear systems.

Usage Guide

Context: mathematics, physics, engineering, computational science

Tone: technical, academic

Origin & History

Sino-Japanese compound: 近 (kin) — near, close + 似 (ji) — to resemble, to be similar. The compound captures the idea of being close to but not identical to the true value, and was adopted in Meiji-era Japan for mathematical and scientific translation.

Cultural Context

Era: Meiji-Modern

Generation: Adult

Social background: Educated