Jacobimatriskalkylator
Beräkna Jacobianen steg för steg
Kalkylatorn kommer att hitta Jakobianmatrisen för uppsättningen av funktioner samt Jakobiandeterminanten (om möjligt) och visa stegen.
Din inmatning
Beräkna Jacobianen för $$$\left\{x = r \cos{\left(\tanh{\left(\eta \right)} \right)}, y = r \sin{\left(\tanh{\left(\eta \right)} \right)}\right\}$$$.
Lösning
Jacobianmatrisen definieras enligt följande: $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}\frac{\partial x}{\partial \eta} & \frac{\partial x}{\partial r}\\\frac{\partial y}{\partial \eta} & \frac{\partial y}{\partial r}\end{array}\right].$$$
I vårt fall gäller $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}\frac{\partial}{\partial \eta} \left(r \cos{\left(\tanh{\left(\eta \right)} \right)}\right) & \frac{\partial}{\partial r} \left(r \cos{\left(\tanh{\left(\eta \right)} \right)}\right)\\\frac{\partial}{\partial \eta} \left(r \sin{\left(\tanh{\left(\eta \right)} \right)}\right) & \frac{\partial}{\partial r} \left(r \sin{\left(\tanh{\left(\eta \right)} \right)}\right)\end{array}\right].$$$
Bestäm derivatorna (för steg, se derivataräknare): $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right]$$$
Jakobideterminanten är determinanten av Jakobimatrisen: $$$\left|\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right| = - r \operatorname{sech}^{2}{\left(\eta \right)}$$$ (för steg, se determinantkalkylator).
Svar
Jacobi-matrisen är $$$\left[\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right].$$$A
Jacobi-determinanten är $$$- r \operatorname{sech}^{2}{\left(\eta \right)}$$$A.