From c0b2d7b11aa1e1ce04d2187538da9f4f4d21c7d3 Mon Sep 17 00:00:00 2001 From: Michael Wimmer <m.t.wimmer@tudelft.nl> Date: Sun, 13 Sep 2020 22:06:18 +0200 Subject: [PATCH] remove explicit conversion to linear system --- src/8_differential_equations_2.md | 23 ----------------------- 1 file changed, 23 deletions(-) diff --git a/src/8_differential_equations_2.md b/src/8_differential_equations_2.md index b8601b0..5286847 100644 --- a/src/8_differential_equations_2.md +++ b/src/8_differential_equations_2.md @@ -153,29 +153,6 @@ $$f(x) = e^{\lambda_1 x}, \ x e^{\lambda_1 x} , \ \cdots, \ x^{m_{1}-1} e^{\lamb $$y'' + Ey = 0.$$ - Let us reduce this second order equation to a system of two first order - equations. Define - - $$y_1=y$$ - $$y_2=y'.$$ - - Writing $**y**= \begin{bmatrix} - y_1 \\ - y_2 \\ - \end{bmatrix}$, the DE can be written, - - $$\dot{**y**} = \begin{bmatrix} - y_2 \\ - -E y_1 \\ - \end{bmatrix}$$ - $$\dot{**y**} = \begin{bmatrix} - 0 & 1 \\ - -E & 0 \\ - \end{bmatrix} \begin{bmatrix} - y_1 \\ - y_2 \\ - \end{bmatrix}.$$ - The characteristic polynomial of this equation is $$P(\lambda) = \lambda^2 + E.$$ -- GitLab