From 516e25958db812634be6c56be07397690e401fba Mon Sep 17 00:00:00 2001 From: Didnelpsun <48906416+Didnelpsun@users.noreply.github.com> Date: Fri, 12 Feb 2021 00:14:02 +0800 Subject: [PATCH] Update differential-mean-value-theorem-and-applications-of-derivatives.tex --- ...tial-mean-value-theorem-and-applications-of-derivatives.tex | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/advanced-math/knowledge/3-differential-mean-value-theorem-and-applications-of-derivatives/differential-mean-value-theorem-and-applications-of-derivatives.tex b/advanced-math/knowledge/3-differential-mean-value-theorem-and-applications-of-derivatives/differential-mean-value-theorem-and-applications-of-derivatives.tex index dc0686c..7865e16 100644 --- a/advanced-math/knowledge/3-differential-mean-value-theorem-and-applications-of-derivatives/differential-mean-value-theorem-and-applications-of-derivatives.tex +++ b/advanced-math/knowledge/3-differential-mean-value-theorem-and-applications-of-derivatives/differential-mean-value-theorem-and-applications-of-derivatives.tex @@ -520,7 +520,7 @@ $\forall x\in U(x_0,\delta)$恒有$f(x)\leqslant f(x_0)$,则$f(x)$在$x_0$取 \item 若参数方程下:$x=\phi(t),y=\psi(t)$,$\rm{d}s=\sqrt{\left(\dfrac{\rm{d}x}{\rm{d}t}\right)^2+\left(\dfrac{\rm{d}y}{\rm{d}t}\right)^2}\rm{d}t$\medskip\\$=\sqrt{\psi'^2(t)+\phi'^2(t)}\rm{d}t$,即$\rm{d}s=\sqrt{\psi'^2(t)+\phi'^2(t)}\rm{d}t$。 \end{itemize} -\subsection{曲率与曲率半径} +\subsection{曲率} 曲率\textcolor{violet}{\textbf{定义:}}表明曲线在某一点的弯曲程度的数值,针对曲线上某个点的切线方向角对弧长的转动率,通过微分来定义,表明曲线偏离直线的程度。曲率越大,表示曲线的弯曲程度越大。 @@ -590,6 +590,7 @@ $\therefore\dfrac{\rm{d}\alpha}{\rm{d}x}=\dfrac{y''}{1+y'^2}\Rightarrow\rm{d}\al $\therefore k=\left\lvert\dfrac{\rm{d}\alpha}{\rm{d}s}\right\rvert=\dfrac{\vert y''\vert}{(1+y'^2)^{\frac{3}{2}}}$。 +\subsection{曲率半径} \begin{minipage}{0.5\linewidth} $\bigcirc O$为函数$L$在点$X$处的曲率圆,该圆与$L$在$X$处相切,切线为$T$。