2023-李林4-1
T5 行变换，行向量组等价；列变换，列向量组等价
T11 \(\displaystyle\int\sqrt{a^2-x^2}\,{\rm d}x=\dfrac{a^2}{2}\arcsin\dfrac{x}{a}+\dfrac{x}{2}\sqrt{a^2-x^2}+{\rm C}\)：前面有平方，后面没有
T12 梯度场有源 \(\nabla\cdot(\nabla u)=(\nabla\cdot\nabla) u=(\dfrac{\part^2}{\part x^2}+\dfrac{\part^2}{\part y^2}+\dfrac{\part^2}{\part z^2})u\)，无旋 \(\nabla\times(\nabla u)=(\nabla\times\nabla) u=0\)
T15 注意这里是 \(6\) 阶行列式（）
标签：四套,dfrac,nabla,sqrt,part,2023,李林 From： https://www.cnblogs.com/guapiii/p/16968262.html