How can I draw graph of sin and put radian units like this picture?

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Laurenso

I am trying to draw the graph of sin interval `[-3pi, 3pi]` like this 
![image.png](/image?hash=c64358538bb308bf3584392b66b2eed2c6e158837ab7dd9ccdc02c0260f362e0)

I tried
```
\documentclass{standalone}
\usepackage   {pgfplots}
\pgfplotsset  {compat=1.17}

\begin{document}
	\begin{tikzpicture}
		\begin{axis}
			[
			domain=-10:10,
			xmin=-10, xmax=10,
			ymin=-1.5, ymax=1.5,
			samples=101,
			axis lines=center,
			ytick=\empty,
			xlabel=$x$,
			ylabel=$y$,
xtick={-9.42478, -6.28319,-4.71239,-3.14,-1.5708,0,1.5708,3.14159,4.71239,6.28319,9.42478},			
xticklabels={$-3\pi$,$-2\pi$,$-\frac{3\pi}{2}$,$-\pi$,$-\frac{\pi}{2}$,$0$,$\frac{\pi}{2}$,$\pi$,  $\frac{3\pi}{2}$, $2\pi$, $3\pi$ }] 
 \addplot[domain=-3*pi:3*pi,samples=100,red,thick]{sin(deg(x))};
 \addplot[domain=-3*pi:3*pi,samples=100,blue,dashed]{-1};
 \addplot[domain=-3*pi:3*pi,samples=100,blue,dashed]{1};
		\end{axis}
		
\end{tikzpicture}
\end{document}
```
I get 
![image.png](/image?hash=20ed735a5857d302363def23e48c85fa17076593f89b370e11f78c30748616e4)

Top Answer

Skillmon

Most likely there is a smart way to achieve this with `pgfplots`, but I'm not good with `pgfplots`, so this just uses Ti*k*Z.

```
\documentclass[border=3.14,tikz]{standalone}

\usetikzlibrary{arrows.meta}

\begin{document}
\begin{tikzpicture}
  \draw[->,>=Stealth]
    (-3*pi-.5,0) coordinate(-x) -- (3*pi+.5,0) coordinate(+x)
    node[below]{$x$}
    ;
  \draw[->,>=Stealth]
    (0,-1.5) -- (0,1.5)
    node[right]{$y$}
    ;
  \foreach\y in {1,-1}
    \draw
      (-.2,\y) -- (.2,\y)
      ;
  \draw[dashed]
    % points on y axis
    (0,-1) node[below left]{$-1$}
    (0,1) node[above left]{$1$}
    % maxima lines
    (-x|-{0,1}) -- (+x|-{0,1})
    (-x|-{0,-1}) -- (+x|-{0,-1})
    % points on x axis
    (-3*pi,0) node[above]{$-3\pi$}
    (-2*pi,0) node[above left]{$-2\pi$}
    (-3*pi/2,0) coordinate(tmp) node[below]{$-\frac{3\pi}{2}$} -- (tmp|-{0,1})
    (-pi,0) node[below left]{$-\pi$}
    (-pi/2,0) coordinate(tmp) node[above]{$-\frac{\pi}{2}$} -- (tmp|-{0,-1})
    (0,0) node[below right]{$O$}
    (pi/2,0) coordinate(tmp) node[below]{$\frac{\pi}{2}$} -- (tmp|-{0,1})
    (pi,0) node[above right]{$\pi$}
    (3*pi/2,0) coordinate(tmp) node[above]{$\frac{3\pi}{2}$} -- (tmp|-{0,-1})
    (2*pi,0) node[below right]{$2\pi$}
    (3*pi,0) node[below]{$3\pi$}
    ;
  \draw[red,thick]
    plot[domain=(-3*pi):(3*pi),samples=101,smooth] (\x,{sin(deg(\x))})
    ;
  \node[above]
    at (5*pi/2,1) {$f(x) = sin(x)$}
    ;
\end{tikzpicture}
\end{document}
```

![sinplotthingy-1.png](/image?hash=c0c0dd964cf4de3ec58043f7d1ea7f36528289b2b6c9d9d732c88c4816bbc092)

Answer #2

Laurenso

I add `width=18cm, 
height=4cm` to my question
```
\begin{tikzpicture}
		\begin{axis}
[width=18cm, 
height=4cm,
domain=-3*pi:3*pi,
			xmin=-3*pi-.5, xmax=3*pi+.5,
			ymin=-1.5, ymax=1.8,
			samples=101,
			axis lines=center,
			ytick=\empty,
			xlabel=$x$,
			ylabel=$y$,
			xtick={-9.42478,-7.85398, -6.28319,-4.71239,-3.14,-1.5708,0,1.5708,3.14159,4.71239,6.28319,7.85398,9.42478},			
			xticklabels={$-3\pi$,$-\frac{5\pi}{2}$,$-2\pi$,$-\frac{3\pi}{2}$,$-\pi$,$-\frac{\pi}{2}$,$0$,$\frac{\pi}{2}$,$\pi$,  $\frac{3\pi}{2}$, $2\pi$, $\frac{5\pi}{2}$,  $3\pi$ }] 
			\addplot[samples=101,red,thick]{sin(deg(x))};
			\addplot[domain=-3*pi-.5:3*pi+.5,samples=101,blue,dashed]{-1};
			\addplot[samples=101,domain=-3*pi-.5:3*pi+.5,blue,dashed]{1};
			\node at (axis cs:0.35, -0.35) {$O$} ; 
			\end{axis}
	\end{tikzpicture}
```
![image.png](/image?hash=047c405c6896c7bd202a7f5d14e41296d92b039cfd8b903ffd39af28bef6418e)

2 Answers