绘制三角函数 tikz

Question

如何使用 tikz/pgfplot 绘制 0-2pi 范围内的以下函数图像？

Answer 1

再举一个例子：

\documentclass[border=5mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}

\begin{document}
    \begin{tikzpicture}[
lbl/.style = {inner sep=0pt,font=\footnotesize,  anchor=#1 west, pos=0.9},    
                        ]
\begin{axis}[
trig format=rad,
%
xlabel = $x$,
ylabel = $f(x)$,
axis lines=middle,
%
xmin=-0.25*pi,  xmax=2.5*pi,
ymin=-0.75,      ymax=1.75,
%
clip=false,
%
xtick={0,pi/2,pi,2*pi,3*pi/2,4*pi},
xticklabels={$0$, $\pi/2$,$\pi$,$3\pi/2$,$2\pi$},
ticklabel style = {font=\scriptsize, inner sep=2pt},
%
domain=0:2*pi,  samples=101, no markers
]
\addplot    {(sqrt(2)/2)*sin(x+5*pi/4)+.5}
    node[lbl=south]   {$f(x)=\frac{\sqrt2}{2} \sin\left(x+\frac{5}{4}\pi\right)$};
\addplot    {(sqrt(2)/2)*cos(x+5*pi/4)+.5}
    node[lbl=north]   {$f(x)=\frac{\sqrt2}{2} \cos\left(x+\frac{5}{4}\pi\right)$};
\end{axis}
    \end{tikzpicture}
\end{document}

Answer 2

像这样：

代码：

\documentclass[border=4mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\begin{document}
    \begin{tikzpicture}
        \begin{axis}[
            clip=false,
            xmin=0,xmax=2.2*pi,
            xlabel= $x$,
            ylabel=$y$,
            ymin=-1.0,ymax=1.5,
            axis lines=middle,
            axis x line=middle,
            axis y line=left,
            %     axis x line=middle,
            xtick={0,1.57,3.14,4.71,6.28},
            xticklabels={$0$, $\frac{\pi}{2}$,$\pi\,$,$\,\,\,\frac{3}{2}\pi$,$\,\,\,2\pi$}
            ]
            \addplot[domain=0:2*pi,samples=200,blue]{.5*sqrt(2)*sin(deg(x+1.25*pi))+.5};
            \addplot[domain=0:2*pi,samples=200,cyan]{.5*sqrt(2)*cos(deg(x+1.25*pi))+.5};
        \end{axis}
    \end{tikzpicture}
\end{document}

Answer 3

\documentclass[border=5mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\begin{document}
  \begin{tikzpicture}
    \begin{axis}[
     clip=false,
     xmin=0,xmax=2.5*pi,
     xlabel= $x$,
     ylabel=$f(x)$,
     ymin=-1.5,ymax=1.5,
     axis lines=middle,
     trig format=rad,
     xtick={0,1.57,3.14,4.71,6.28},
     xticklabels={$0$, $\frac{\pi}{2}$,$\pi\,$,$\,\,\,\frac{3}{2}\pi$,$\,\,\,2\pi$},
     ]
      \addplot[domain=0:2*pi,samples=200,red]{(sqrt(2)/2)*sin(x+5*pi/4)+.5}
                                node[right,pos=0.75,font=\footnotesize]{$f(x)=\frac{\sqrt2}{2} \sin\left(x+\frac{5}{4}\pi\right)$};
      \addplot[domain=0:2*pi,samples=200,orange]{(sqrt(2)/2)*cos(x+5*pi/4)+.5}
                                node[left,pos=1.5,font=\footnotesize]{$f(x)=\frac{\sqrt2}{2} \cos\left(x+\frac{5}{4}\pi\right)$};
        \end{axis}
  \end{tikzpicture}
\end{document}