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# TikZ: an integer number line

TikZ does the math for you - tell it you want to put something at $$(\sqrt{2}+\sqrt{3}, 0)$$ and it will calculate the exact location.

\#+begin_src latex :file ./img/cohen-precalc-1.1B.png :imagemagick yes :results output silent :fit yes :imoutoptions -geometry 900 :iminoptions -density 600

\begin{tikzpicture}[
>=Stealth,
define rgb/.code={\definecolor{mycolor}{RGB}{#1}},
rgb color/.style={define rgb={#1},mycolor}
]
% x-axis
\draw[<->] (-5,0) -- (5,0);

% 11
\fill[black] (11/4,0) circle (0.4 mm) node[above=6pt] {\scriptsize\strut $11/4$};
\draw (11/4,0) -- ++(0,7pt);

% 12
\fill[black] (-7/8,0) circle (0.4 mm) node[above=6pt] {\scriptsize\strut $-7/8$};
\draw (-7/8,0) -- ++(0,7pt);

% 13
\fill[black] ({sqrt(2) + 1},0) circle (0.4 mm) node[above=20pt] {\scriptsize\strut $1+\sqrt{2}$};
\draw ({sqrt(2) + 1},0) -- ++(0,22pt);

% 14
\fill[black] ({1-sqrt(2)},0) circle (0.4 mm) node[above=20pt] {\scriptsize\strut $1-\sqrt{2}\quad$};
\draw ({1-sqrt(2)},0) -- ++(0,22pt);

% 15
\fill[black] ({sqrt(2)-1},0) circle (0.4 mm) node[above=20pt] {\scriptsize\strut $\quad\sqrt{2}-1$};
\draw ({sqrt(2)-1},0) -- ++(0,22pt);

% 16
\fill[black] ({-sqrt(2)-1},0) circle (0.4 mm) node[above=20pt] {\scriptsize\strut $-\sqrt{2}-1$};
\draw ({-sqrt(2)-1},0) -- ++(0,22pt);

% 17
\fill[black] ({sqrt(2)+sqrt(3)},0) circle (0.4 mm) node[above=32pt] {\scriptsize\strut $\sqrt{2}+\sqrt{3}$};
\draw ({sqrt(2)+sqrt(3)},0) -- ++(0,34pt);

% 18
\fill[black] ({sqrt(2)-sqrt(3)},0) circle (0.4 mm) node[below=20pt] {\scriptsize\strut $\sqrt{2}-\sqrt{3}$};
\draw ({sqrt(2)-sqrt(3)},0) -- ++(0,-22pt);

% 19
\fill[black] ({(1+sqrt(2))/2},0) circle (0.4 mm) node[below=20pt] {\scriptsize\strut $(1+\sqrt{2})/2$};
\draw ({(1+sqrt(2))/2},0) -- ++(0,-22pt);

% 20
\fill[black] ({(2*sqrt(3)+1)/2},0) circle (0.4 mm) node[below=32pt] {\scriptsize\strut $(2\sqrt{3}+1)/2$};
\draw ({(2*sqrt(3)+1)/2},0) -- ++(0,-34pt);

% labeled dots in Cohen Precalculus 4ed blue
\foreach \i in {-4,-3,...,4} % points on line
\fill
[rgb color={0,165,214}]
(\i,0)
circle (0.8 mm)
node[below=6pt,black] {$\i$};

\end{tikzpicture}


ยท Emacs 30.0.50 (Org mode 9.6.11)