derivative of a real function
导数
Meaning in context
For a real function defined near a, its derivative at a is the finite limit of (f(a+h)-f(a))/h as nonzero h tends to zero.
实函数在点 a 附近有定义,若增量商 (f(a+h)-f(a))/h 在 h 趋于零时有有限极限,该极限就是 a 处的导数。
Example
For , .
Usage and distinctions
A two-sided derivative requires agreement of the left and right limits.
Read the encyclopedia explanation
Recommended reading in this subject · Preparation & skip guidance
Definition sources
- Michael Taylor — Introduction to Analysis in One Variable§4.1, equations (4.1.1)–(4.1.3) · Checked 2026-10-14
Translation sources
- 中国矿业大学数学学院 — 数学分析讲义,第五章§1 导数的概念 · Checked 2026-10-14