\documentclass[a4paper,10pt]{article} \usepackage{myXsim} \usepackage{pgfplots} % \pgfplotsset{compat = newest} % \usepgfplotslibrary{external} % \tikzexternalize % Title Page \title{DM 3 \hfill \Var{Nom}} \tribe{2nd6} \date{À rendre pour mardi 25 janvier 2022} \xsimsetup{ solution/print = false } \begin{document} \maketitle \begin{exercise}[subtitle={Calculs de fractions}, points=2] Détailler les calculs suivants et donner le résultat sous la forme d'une fraction irréductible. \begin{multicols}{3} \begin{enumerate}[label={\Alph*=}] %- set A = rdm.expression("{a} / {b} + {c}", ["a!=b", "b > 1"], global_config={"min_max":(1, 10)}) \item $\Var{A}$ %- set B = rdm.expression("{a} / {b} + {c} / {d}", ["a!=b", "b > 1"], global_config={"min_max":(-10, 10), "rejected":[-1, 0, 1]}) \item $\Var{B}$ %- set C = rdm.expression("{a} / {b} * {c} / {k*b}", ["a!=b", "c!=b", "b > 1"], global_config={"min_max":(1, 10)}) \item $\Var{C}$ \end{enumerate} \end{multicols} \end{exercise} \begin{solution} \begin{enumerate}[label={\Alph*=}] \item $\Var{A.simplify().explain() | join('=')} = \Var{A.simplify().simplified}$ \item $\Var{B.simplify().explain() | join('=')} = \Var{B.simplify().simplified}$ \item $\Var{C.simplify().explain() | join('=')} = \Var{C.simplify().simplified}$ \end{enumerate} \end{solution} \begin{exercise}[subtitle={Développer}, points=2] Développer puis réduire les expressions suivantes \begin{multicols}{3} \begin{enumerate}[label={\Alph*=}] %- set A = rdm.expression("{a}x({c}x+{d}) - {b}x", [], global_config={"min_max":(1, 10)}) \item $\Var{A}$ %- set B = rdm.expression("({a}x+{b})({c}x+{d})", [], ) \item $\Var{B}$ %- set C = rdm.expression("({a}x+{b})^2", [], ) \item $\Var{C}$ \end{enumerate} \end{multicols} \end{exercise} \begin{solution} \begin{enumerate} \item \begin{align*} A &= \Var{A.simplify().explain() | join('\\\\&=')} \end{align*} \item \begin{align*} B &= \Var{B.simplify().explain() | join('\\\\&=')} \end{align*} \item \begin{align*} C &= \Var{C.simplify().explain() | join('\\\\&=')} \end{align*} \end{enumerate} \end{solution} \begin{exercise}[subtitle={Inéquation et tableaux}, points=3] Tracer le tableau de signe des fonctions suivantes en le démontrant à l'aide de la résolution d'une inéquation. \begin{multicols}{2} \begin{enumerate} %- set f = rdm.expression("{a}x + {b}", global_config={"min_max":(1, 20)}) \item $f(x) = \Var{f}$ %- set g = rdm.expression("{a}x + {b}", global_config={"min_max":(1, 20)}) \item $g(x) = \Var{g}$ \end{enumerate} \end{multicols} \end{exercise} \begin{solution} \begin{enumerate} \item Pour déterminer les valeurs de $x$ pour lesquelles $f(x)$ est positive, il faut résoudre l'inéquation %- set cst = -f[0] %- set coef = f[1] %- set racine = cst / coef \begin{align*} f(x) & \geq 0 \\ \Var{f} & \geq 0 \\ \Var{f + cst} &\geq \Var{0 + cst} \\ \frac{\Var{f + cst}}{\Var{coef}} &\geq \frac{\Var{cst}}{\Var{coef}} \\ x &\geq \Var{racine.simplify()} \\ \end{align*} Donc $f(x)$ est positif quand $x$ est supérieur à $\Var{racine}$. On en déduit le tableau de signe \begin{center} \begin{tikzpicture} \tkzTabInit[lgt=2,espcl=1]{$ t $/1,$ f(t) $/1}{, $\Var{racine}$ ,} \tkzTabLine{, -, z, +, } \end{tikzpicture} \end{center} \item Pour déterminer les valeurs de $x$ pour lesquelles $g(x)$ est positive, il faut résoudre l'inéquation %- set cst = -g[0] %- set coef = g[1] %- set racine = cst / coef \begin{align*} g(x) & \geq 0 \\ \Var{g} & \geq 0 \\ \Var{g + cst} &\geq \Var{0 + cst} \\ \frac{\Var{g + cst}}{\Var{coef}} &\geq \frac{\Var{cst}}{\Var{coef}} \\ x &\geq \Var{racine.simplify()} \\ \end{align*} Donc $f(x)$ est positif quand $x$ est supérieur à $\Var{racine}$. On en déduit le tableau de signe \begin{center} \begin{tikzpicture} \tkzTabInit[lgt=2,espcl=1]{$ t $/1,$ g(t) $/1}{, $\Var{racine}$ ,} \tkzTabLine{, -, z, +, } \end{tikzpicture} \end{center} \end{enumerate} \end{solution} \begin{exercise}[subtitle={Vecteurs}, points=2] \begin{enumerate} \item Tracer les vecteurs $\vect{z} = \vect{u} + \vect{v}$ et $\vect{y} = 2\vect{u} - \vect{v}$ (le vecteur peur sortir du cadre) %- set xa1, ya1 = rdm.list(["x", "y"], global_config={"min_max": (-5, 5), "rejected":[-2, -1, 0, 1, 2]}) %- set xa2, ya2 = -xa1, ya1 %- set aminx = min(0, xa1, xa2, xa1+xa2, 2*xa1-xa2) %- set amaxx = max(0, xa1, xa2, xa1+xa2, 2*xa1-xa2) %- set aminy = min(0, ya1, ya2, ya1+ya2, 2*ya1-ya2) %- set amaxy = max(0, ya1, ya2, ya1+ya2, 2*ya1-ya2) \begin{center} \begin{tikzpicture}[scale=0.4] \draw (\Var{aminx-1}, \Var{aminy-1}) rectangle (\Var{amaxx+1}, \Var{amaxy+1}); \draw[very thick, ->] (0, 0) -- node [midway, sloped, above] {$\vect{u}$} (\Var{xa1}, \Var{ya1}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{v}$} (\Var{xa2}, \Var{ya2}); \end{tikzpicture} \end{center} \item Tracer la force résultat de la somme des 3 forces exercées sur le point $0$ représenté ci-dessous. %- set x1, y1 = rdm.list(["x", "y"], global_config={"min_max": (-5, 5), "rejected":[-2, -1, 0, 1, 2]}) %- set x2, y2 = -x1, y1 %- set x3, y3 = x2, 0 %- set minx = min(0, x1, x2, x3, x1+x2, x2+x3, x1+x3, x1+x2+x3 ) %- set maxx = max(0, x1, x2, x3, x1+x2, x2+x3, x1+x3, x1+x2+x3 ) %- set miny = min(0, y1, y2, y3, y1+y2, y2+y3, y1+y3, y1+y2+y3 ) %- set maxy = max(0, y1, y2, y3, y1+y2, y2+y3, y1+y3, y1+y2+y3 ) \begin{center} \begin{tikzpicture}[scale=0.4] \draw (\Var{minx-1}, \Var{miny-1}) rectangle (\Var{maxx+1}, \Var{maxy+1}); \draw[very thick, ->] (0, 0) -- node [midway, sloped, above] {$\vect{F_1}$} (\Var{x1}, \Var{y1}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{F_2}$} (\Var{x2}, \Var{y2}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{F_3}$} (\Var{x3}, \Var{y3}); \end{tikzpicture} \end{center} \end{enumerate} \end{exercise} \begin{solution} \begin{enumerate} \item \begin{center} \begin{tikzpicture}[scale=0.4] \draw (\Var{aminx-1}, \Var{aminy-1}) rectangle (\Var{amaxx+1}, \Var{amaxy+1}); \draw[very thick, ->] (0, 0) -- node [midway, sloped, above] {$\vect{u}$} (\Var{xa1}, \Var{ya1}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{v}$} (\Var{xa2}, \Var{ya2}); \draw[very thick, ->, color=blue] (0, 0) -- ++ (\Var{xa1}, \Var{ya1}) node [midway, sloped, above] {$\vect{u}$} -- ++ (\Var{xa2}, \Var{ya2}) node [midway, sloped, above] {$\vect{v}$} ; \draw[very thick, ->, color=blue] (0, 0) -- node [midway, sloped, left] {$\vect{z}$} (\Var{xa2+xa1}, \Var{ya2+ya1}); \draw[very thick, ->, color=green] (0, 0) -- ++ (\Var{xa1}, \Var{ya1}) node [midway, sloped, above] {$\vect{u}$} -- ++ (\Var{xa1}, \Var{ya1}) node [midway, sloped, above] {$\vect{u}$} -- ++ (-\Var{xa2}, -\Var{ya2}) node [midway, sloped, above] {$-\vect{v}$} ; \draw[very thick, ->, color=green] (0, 0) -- node [midway, sloped, above] {$\vect{y}$} (\Var{2*xa1 - xa2}, \Var{2*ya1 - ya2}); \end{tikzpicture} \end{center} \item \begin{center} \begin{tikzpicture}[scale=0.4] \draw (\Var{minx-1}, \Var{miny-1}) rectangle (\Var{maxx+1}, \Var{maxy+1}); \draw[very thick, ->] (0, 0) -- node [midway, sloped, above] {$\vect{F_1}$} (\Var{x1}, \Var{y1}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{F_2}$} (\Var{x2}, \Var{y2}); \draw[very thick, -> ] (0, 0) -- node [midway, sloped, above] {$\vect{F_3}$} (\Var{x3}, \Var{y3}); \draw[very thick, ->, color=blue] (0, 0) --++ (\Var{x1}, \Var{y1}) node [midway, sloped, above] {$\vect{F_1}$} --++ (\Var{x2}, \Var{y2}) node [midway, sloped, above] {$\vect{F_2}$} --++ (\Var{x3}, \Var{y3}) node [midway, sloped, above] {$\vect{F_3}$} ; \draw[very thick, ->, color=blue] (0, 0) -- (\Var{x1+x2+x3}, \Var{y1+y2+y3}) node [midway, sloped, above] {$\vect{F_1}+\vect{F_2}+\vect{F_3}$}; \end{tikzpicture} \end{center} \end{enumerate} \end{solution} \end{document}