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