Secant Line

Core Sentence / 核心句

A secant line passes through two points on a curve and represents average change over an interval.

中文理解：割线连两个点，对应一段区间的平均变化。

Formula / 公式或规则

$$m_{\text{secant}}=\frac{f(b)-f(a)}{b-a}$$

When To Use / 什么时候用

看到 between two points、average slope、average rate，就想到 secant line。

Watch Out / 易错点

secant line 是两点，tangent line 是一点附近的极限。

Search and Source Mentions / 搜索与出现位置

Mentioned In / 出现位置

• 02 - The Paradox of the Derivative · Knowledge Point 6: Secant Line Becomes Tangent Line
  • Knowledge Point 6: Secant Line Becomes Tangent Line
• 02 - The Paradox of the Derivative · Knowledge Point 3: Average Velocity Needs Two Times
  • average velocity -> slope of secant line

Connected Notes / 连接

• 02 - The Paradox of the Derivative
• Average Rate of Change
• Tangent Line
• Limits