Jacobin matriisin laskin
Laske Jakobin matriisi vaiheittain
Laskin laskee funktioiden joukon Jacobin matriisin ja Jacobin determinantin (jos mahdollista) sekä näyttää vaiheet.
Syötteesi
Laske $$$\left\{x = r \cos{\left(\tanh{\left(\eta \right)} \right)}, y = r \sin{\left(\tanh{\left(\eta \right)} \right)}\right\}$$$:n Jakobiaani.
Ratkaisu
Jakobin matriisi määritellään seuraavasti: $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}\frac{\partial x}{\partial \eta} & \frac{\partial x}{\partial r}\\\frac{\partial y}{\partial \eta} & \frac{\partial y}{\partial r}\end{array}\right].$$$
Meidän tapauksessamme pätee $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}\frac{\partial}{\partial \eta} \left(r \cos{\left(\tanh{\left(\eta \right)} \right)}\right) & \frac{\partial}{\partial r} \left(r \cos{\left(\tanh{\left(\eta \right)} \right)}\right)\\\frac{\partial}{\partial \eta} \left(r \sin{\left(\tanh{\left(\eta \right)} \right)}\right) & \frac{\partial}{\partial r} \left(r \sin{\left(\tanh{\left(\eta \right)} \right)}\right)\end{array}\right].$$$
Laske derivaatat (vaiheet: katso derivointilaskuri): $$$J{\left(x,y \right)}\left(\eta, r\right) = \left[\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right].$$$
Jacobin determinantti on Jacobin matriisin determinantti: $$$\left|\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right| = - r \operatorname{sech}^{2}{\left(\eta \right)}$$$ (vaiheet, ks. determinanttilaskin).
Vastaus
Jacobin matriisi on $$$\left[\begin{array}{cc}- r \sin{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \cos{\left(\tanh{\left(\eta \right)} \right)}\\r \cos{\left(\tanh{\left(\eta \right)} \right)} \operatorname{sech}^{2}{\left(\eta \right)} & \sin{\left(\tanh{\left(\eta \right)} \right)}\end{array}\right].$$$A
Jacobin determinantti on $$$- r \operatorname{sech}^{2}{\left(\eta \right)}$$$A.