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Henrik Holst edited Ellipsens_ekvation_E_x_frac__.tex
almost 9 years ago
Commit id: 919b3d2561aefed3da999b2d6bf79b66927a221d
deletions | additions
diff --git a/Ellipsens_ekvation_E_x_frac__.tex b/Ellipsens_ekvation_E_x_frac__.tex
index def7ebc..41da54f 100644
--- a/Ellipsens_ekvation_E_x_frac__.tex
+++ b/Ellipsens_ekvation_E_x_frac__.tex
...
$$E(x) := \frac{x_1^2}{e_1^2} + \frac{x_2^2}{e_2^2} + \frac{x_3^2}{e_3^2} - 1 = 0$$
Vi har en punkt $y$ utanför ellipsoiden:
$$y = \begin{bmatrix} y_1 & y_2 & y_3 \end{bmatrix}$$
Vi har
för en punkt $x$ på ellipsen:
$$y - x = \frac{1}{2} t \nabla E(x) = t \begin{bmatrix} \frac{x_1}{e_1^2} & \frac{x_2}{e_2^2} & \frac{x_3}{e_3^2} \end{bmatrix}$$
eller ekvivalent formulerat
$$y_k = \left( 1 + \frac{t}{e_k^2} \right) x_k, \qquad k=1,2,3.$$
...
$$E'(t)=-\frac{y_1^2}{(t+e_1^2)^2} - \frac{y_2^2}{(t+e_2^2)^2} - \frac{y_3^2}{(t+e_3^2)^2}$$