1. 雅可比式
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1.1 概念
雅可比式也称为函数行列式,它是用来描述变量与变量之间变换关系的。假设x,y∈Rnx,y\in R^nx,y∈Rn,并且两者之间线性变换关系y=Ax+μy = Ax + \muy=Ax+μ(也可以展开表示为方程组形式),则雅可比式可以表示为
J=∣dy1dx1...dy1dxndy2dx1...dy2dxn..........dyndx1...dyndxn∣ J=\begin {vmatrix} \frac{dy_1}{dx_1} & ... & \frac{dy_1}{dx_n} \\ \frac{dy_2}{dx_1} & ... & \frac{dy_2}{dx_n} \\ . & ... & . \\ . & ... & . \\ \frac{dy_n}{dx_1} &... & \frac{dy_n}{dx_n} \end{vmatrix} J=∣∣∣∣∣∣∣∣∣∣∣dx1dy1dx1dy2..dx1dyn...............dxndy1dxndy2..dxndyn