Prima di ogni figura ricordare di mettere
\documentclass[usenames,dvipsnames]{article}
\usepackage{pgfplots}
Prima figura
Codice prima figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -8,
xmax = 16,
ymin = -5,
ymax = 12,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{-0.2cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=12:-12,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) (10,10) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {(10,10)} node[below right] {$C=(x,x)$};
\end{axis}
\end{tikzpicture}
Seconda figura
Codice seconda figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -5,
xmax = 4,
ymin = -4,
ymax = 4,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{0.4cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=3:-3,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) (-1,-1) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {(-1,-1)} node[above left] {$C=(-1,-1)$};
\end{axis}
\end{tikzpicture}
Terza figura
Codice terza figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -4,
xmax = 6,
ymin = -4,
ymax = 4,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{0.4cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=4:-2,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) (2,2) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {(2,2)} node[below right] {$C=(2,2)$};
\end{axis}
\end{tikzpicture}
Quarta figura
Codice quarta figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -7,
xmax = 10,
ymin = -7,
ymax = 7,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{0.4cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=7:-5,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) (4,4) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {(4,4)} node[below right] {$C=(4,4)$};
\end{axis}
\end{tikzpicture}
Quinta figura
Codice quinta figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -8,
xmax = 4,
ymin = -4,
ymax = 4,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{0.4cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=3.5:-4,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) ({-sqrt(6)},{-sqrt(6)}) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {({-sqrt(6)},{-sqrt(6)})} node[above left] {$C=(-\sqrt{6},-\sqrt{6})$};
\end{axis}
\end{tikzpicture}
Sesta figura
Codice sesta figura
\begin{tikzpicture}
\begin{axis}[
xtick = \empty,
ytick = \empty,
axis equal image,
axis x line=center,
axis y line=center,
xmin = -4,
xmax = 8,
ymin = -4,
ymax = 7,
xlabel = {$x$},
ylabel = {$y$},
extra x ticks = {0},
extra x tick label = {$\hspace{0.4cm}0$},
y label style={anchor=north east}
]
\addplot[very thick,samples=100,domain=6:-3,,Purple] {x};
\addplot[mark=*,very thick,red] coordinates { (2,-2) (0,2) ({sqrt(6)},{sqrt(6)}) (2,-2)};
\addplot[mark=*] coordinates {(2,-2)} node[below left] {$A$};
\addplot[mark=*] coordinates {(0,2)} node[below left] {$B$};
\addplot[mark=*] coordinates {({sqrt(6)},{sqrt(6)})} node[below right] {$C=(\sqrt{6},\sqrt{6})$};
\end{axis}
\end{tikzpicture}