%%===================================================================================== %% %% Filename: cours.tex %% %% Description: %% %% Version: 1.0 %% Created: 03/06/2024 %% Revision: none %% %% Author: YOUR NAME (), %% Organization: %% Copyright: Copyright (c) 2024, YOUR NAME %% %% Notes: %% %%===================================================================================== \documentclass[a4paper, titlepage]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{textcomp} \usepackage[french]{babel} \usepackage{amsmath, amssymb} \usepackage{amsthm} \usepackage[svgnames]{xcolor} \usepackage{thmtools} \usepackage{lipsum} \usepackage{framed} \usepackage{parskip} \usepackage{titlesec} \renewcommand{\familydefault}{\sfdefault} % figure support \usepackage{import} \usepackage{xifthen} \pdfminorversion=7 \usepackage{pdfpages} \usepackage{transparent} \newcommand{\incfig}[1]{% \def\svgwidth{\columnwidth} \import{./figures/}{#1.pdf_tex} } \pdfsuppresswarningpagegroup=1 \colorlet{defn-color}{DarkBlue} \colorlet{props-color}{Blue} \colorlet{warn-color}{Red} \colorlet{exemple-color}{Green} \colorlet{corol-color}{Orange} \newenvironment{defn-leftbar}{% \def\FrameCommand{{\color{defn-color}\vrule width 3pt} \hspace{10pt}}% \MakeFramed {\advance\hsize-\width \FrameRestore}}% {\endMakeFramed} \newenvironment{warn-leftbar}{% \def\FrameCommand{{\color{warn-color}\vrule width 3pt} \hspace{10pt}}% \MakeFramed {\advance\hsize-\width \FrameRestore}}% {\endMakeFramed} \newenvironment{exemple-leftbar}{% \def\FrameCommand{{\color{exemple-color}\vrule width 3pt} \hspace{10pt}}% \MakeFramed {\advance\hsize-\width \FrameRestore}}% {\endMakeFramed} \newenvironment{props-leftbar}{% \def\FrameCommand{{\color{props-color}\vrule width 3pt} \hspace{10pt}}% \MakeFramed {\advance\hsize-\width \FrameRestore}}% {\endMakeFramed} \newenvironment{corol-leftbar}{% \def\FrameCommand{{\color{corol-color}\vrule width 3pt} \hspace{10pt}}% \MakeFramed {\advance\hsize-\width \FrameRestore}}% {\endMakeFramed} \def \freespace {1em} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{defn-color}Définition~\NUMBER\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{defn-leftbar},% postfoothook=\end{defn-leftbar},% ]{better-defn} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{warn-color}Attention\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{warn-leftbar},% postfoothook=\end{warn-leftbar},% ]{better-warn} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{exemple-color}Exemple~\NUMBER\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{exemple-leftbar},% postfoothook=\end{exemple-leftbar},% ]{better-exemple} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{props-color}Proposition~\NUMBER\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{props-leftbar},% postfoothook=\end{props-leftbar},% ]{better-props} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{props-color}Théorème~\NUMBER\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{props-leftbar},% postfoothook=\end{props-leftbar},% ]{better-thm} \declaretheoremstyle[headfont=\sffamily\bfseries,% notefont=\sffamily\bfseries,% notebraces={}{},% headpunct=,% bodyfont=\sffamily,% headformat=\color{corol-color}Corollaire~\NUMBER\hfill\NOTE\smallskip\linebreak,% preheadhook=\vspace{\freespace}\begin{corol-leftbar},% postfoothook=\end{corol-leftbar},% ]{better-corol} \declaretheorem[style=better-defn]{defn} \declaretheorem[style=better-warn]{warn} \declaretheorem[style=better-exemple]{exemple} \declaretheorem[style=better-corol]{corol} \declaretheorem[style=better-props, numberwithin=defn]{props} \declaretheorem[style=better-thm, sibling=props]{thm} \newtheorem*{lemme}{Lemme}%[subsection] %\newtheorem{props}{Propriétés}[defn] \newenvironment{system}% {\left\lbrace\begin{align}}% {\end{align}\right.} \newenvironment{AQT}{{\fontfamily{qbk}\selectfont AQT}} \usepackage{LobsterTwo} \titleformat{\section}{\newpage\LobsterTwo \huge\bfseries}{\thesection.}{1em}{} \titleformat{\subsection}{\vspace{2em}\LobsterTwo \Large\bfseries}{\thesubsection.}{1em}{} \titleformat{\subsubsection}{\vspace{1em}\LobsterTwo \large\bfseries}{\thesubsubsection.}{1em}{} \newenvironment{lititle}% {\vspace{7mm}\LobsterTwo \large}% {\\} \renewenvironment{proof}{$\square$ \footnotesize\textit{Démonstration.}}{\begin{flushright}$\blacksquare$\end{flushright}} \title{TD du 13 février} \author{William Hergès\thanks{Sorbonne Université - Faculté des Sciences, Faculté des Lettres}} \begin{document} \maketitle \newpage \section*{Exercice 1} Trivial \section*{Exercice 2} Trivial \section*{Exercice 3} Trivial \section*{Exercice 4} On a : \begin{align*} 2 &= a-b+c \\ 1 &= a+b-c \\ 3 &= -a+b+c \end{align*} où $(a,b,c)$ sont les coordonnées du vecteur dans la base. D'où : $$\begin{pmatrix} 1&-1&1&|&2\\1&1&-1&|&1\\-1&1&1&|&3 \end{pmatrix}\iff\begin{pmatrix} 1&-1&1&|&2\\0&2&-2&|&-1\\0&0&2&|&5\end{pmatrix}$$ Ainsi, \begin{align*} c &= 5/2 \\ b &= 2 \\ a &= 3/2 \end{align*} \section*{Exercice 5} Si $x=0$, alors $v = u + w$, donc ce n'est pas libre.\\ Si $x\neq 0$, alors $(uvx)$ est échelonné, donc elle est libre. Il s'agit d'une base si et seulement si $x\neq 0$. \section*{Exercice 6} \begin{lititle} Matrice de changement de base. \end{lititle} On a $v$ un vecteur dans la base canonique. $\lambda$ est dans la base $A$ et $\mu$ dans la base $B$. Ainsi, on a : \begin{align*} \mathrm{I}_n v &= A\lambda \\ \mathrm{I}_n v &= B\mu \end{align*} d'où : $$ A\lambda = B\mu \iff \mu = B^{-1}A\lambda $$ Ainsi, $B^{-1}A$ est la matrice de passage de $A$ à $B$. \section*{Exercice 7} $\lambda v_1+v_2 = (\lambda x_1+x_2,\lambda y_1 + y_2)$\\ $\lambda y_1+y_2=\lambda x_1+x_2+\lambda+1 \neq \lambda x_1+x_2+1$\\ donc $A$ n'est pas un sev. $\lambda v_1+v_2 = (\lambda x_1 + x_2, \lambda x_1 + x_2)$\\ donc $A_1$ est un sev. $\lambda v_1+v_2 = (\lambda x_1+x_2,\lambda y_1 + y_2)$\\ $\lambda y_1 = \lambda^2 x^2 \neq x^2$\\ donc $A_2$ n'est pas un sev. \end{document}