From 44d89c801da442a466e3e0982c72bba3a0e8c5dc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christoffer=20M=C3=BCller=20Madsen?= Date: Fri, 9 Jun 2017 20:32:10 +0200 Subject: [PATCH] =?UTF-8?q?halvvejs=20f=C3=A6rdig=20med=20emne=205?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- beviser.lyx | 233 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 231 insertions(+), 2 deletions(-) diff --git a/beviser.lyx b/beviser.lyx index cf0d2bd..6261979 100644 --- a/beviser.lyx +++ b/beviser.lyx @@ -1680,7 +1680,7 @@ For en samling af elementer \begin_inset Formula $V$ \end_inset -gælder det at + gælder det at \end_layout \begin_layout Enumerate @@ -1921,7 +1921,11 @@ Hvis kan \emph on -udvides +ud +\emph default +koordinattransformationsmatricer +\emph on +vides \emph default til en basis for \begin_inset Formula $V$ @@ -2249,5 +2253,230 @@ Noter Overvej at droppe Lemma 7.2 fra dispositionen. \end_layout +\begin_layout Standard +\begin_inset Newpage newpage +\end_inset + + +\end_layout + +\begin_layout Section +Matrixrepræsentationer +\end_layout + +\begin_layout Subsection +Definition 8.3 ( +\emph on +Koordinatvektor +\emph default +) +\end_layout + +\begin_layout Standard +\begin_inset Formula $\mathcal{V}=(\boldsymbol{v}_{1},\boldsymbol{v}_{2},\dots,\boldsymbol{v}_{n})$ +\end_inset + + er en basis for et +\begin_inset Formula $\mathbb{F}$ +\end_inset + +-vektorrum +\begin_inset Formula $V$ +\end_inset + +. + +\emph on +Koordinatvektoren +\emph default + for et element +\begin_inset Formula $\boldsymbol{v}\in V$ +\end_inset + + mht. + basen +\begin_inset Formula $\mathcal{V}$ +\end_inset + + menes elementet +\begin_inset Formula $L_{\mathcal{V}}^{-1}(\boldsymbol{v})\in\mathbb{F}^{n}$ +\end_inset + +. + Koordinatvektoren kan også betegnes med +\begin_inset Formula $\left[\boldsymbol{v}\right]_{\mathcal{V}}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Koordinatvektoren er den vektor +\begin_inset Formula +\[ +\begin{pmatrix}\alpha_{1}\\ +\alpha_{2}\\ +\vdots\\ +\alpha_{n} +\end{pmatrix}\in\mathbb{F}^{n} +\] + +\end_inset + +som opfylder relationen +\begin_inset Formula +\[ +\boldsymbol{v}=\alpha_{1}\cdot\boldsymbol{v}_{1}+\alpha_{2}\cdot\boldsymbol{v}_{2}+\cdots+\alpha_{n}\cdot\boldsymbol{v}_{n}. +\] + +\end_inset + + +\end_layout + +\begin_layout Subsection +Definition 8.6 ( +\emph on +Koordinattransformationsmatricen +\emph default +) +\end_layout + +\begin_layout Standard +Lad +\begin_inset Formula $\mathcal{V}=(\boldsymbol{v}_{1},\boldsymbol{v}_{2},\dots,\boldsymbol{v}_{n})$ +\end_inset + + og +\begin_inset Formula $\mathcal{W}=(\boldsymbol{w}_{1},\boldsymbol{w}_{2},\dots,\boldsymbol{w}_{n})$ +\end_inset + + være baser for det samme +\begin_inset Formula $\mathbb{F}$ +\end_inset + +-vektorrum +\begin_inset Formula $V$ +\end_inset + +. + +\emph on +Koordinattransformationsmatricen for overgangen fra +\begin_inset Formula $\mathcal{W}$ +\end_inset + +-basen til +\begin_inset Formula $\mathcal{V}$ +\end_inset + +-basen defineres som matricen +\begin_inset Formula +\[ +_{\underset{til}{\underbrace{\mathcal{V}}}}\left[\boxempty\right]_{\underset{fra}{\underbrace{\mathcal{W}}}}=\begin{pmatrix}\vline & \vline & & \vline\\ +\left[\boldsymbol{w}_{1}\right]_{\mathcal{V}} & \left[\boldsymbol{w}_{2}\right]_{\mathcal{V}} & \cdots & \left[\boldsymbol{w}_{n}\right]_{\mathcal{V}}\\ +\vline & \vline & & \vline +\end{pmatrix}\in{\rm Mat_{n}(\mathbb{F})} +\] + +\end_inset + + +\end_layout + +\begin_layout Subsection +Definition 8.9 ( +\emph on +Matrixrepræsentation +\emph default +) +\end_layout + +\begin_layout Standard +Lad +\begin_inset Formula $L:\:W\rightarrow V$ +\end_inset + + betegne en lineær afbildning mellem +\begin_inset Formula $\mathbb{F}$ +\end_inset + +-vektorrum +\begin_inset Formula $W$ +\end_inset + + og +\begin_inset Formula $V$ +\end_inset + + med baser hhv. + +\begin_inset Formula $\mathcal{W}=(\boldsymbol{w}_{1},\boldsymbol{w}_{2},\dots,\boldsymbol{w}_{n})$ +\end_inset + + og +\begin_inset Formula $\mathcal{V}=(\boldsymbol{v}_{1},\boldsymbol{v}_{2},\dots,\boldsymbol{v}_{n})$ +\end_inset + + . + +\emph on +Matrixrepræsentationen +\emph default + for +\begin_inset Formula $L$ +\end_inset + + mht. + til baserne +\begin_inset Formula $\mathcal{W}$ +\end_inset + + og +\begin_inset Formula $\mathcal{V}$ +\end_inset + + defineres da som matricen +\end_layout + +\begin_layout Standard + +\emph on +\begin_inset Formula +\[ +_{\underset{til}{\underbrace{\mathcal{V}}}}\left[L\right]_{\underset{fra}{\underbrace{\mathcal{W}}}}=\begin{pmatrix}\vline & \vline & & \vline\\ +\left[L(\boldsymbol{w}_{1})\right]_{\mathcal{V}} & \left[L(\boldsymbol{w}_{2})\right]_{\mathcal{V}} & \cdots & \left[(\boldsymbol{w}_{n})\right]_{\mathcal{V}}\\ +\vline & \vline & & \vline +\end{pmatrix}\in{\rm Mat_{n}(\mathbb{F})} +\] + +\end_inset + + +\end_layout + +\begin_layout Subsection +Proposition 8.10(1) (Matrixrepræsentationer og koordinatvektorer) +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +\left[L(\boldsymbol{v})\right]_{\mathcal{W}}={}_{\mathcal{V}}\left[L\right]_{\mathcal{W}}\cdot\left[\boldsymbol{v}\right]_{\mathcal{V}}. +\] + +\end_inset + + +\end_layout + +\begin_layout Subsection +Lemma 8.19 +\end_layout + +\begin_layout Standard + +\end_layout + \end_body \end_document