[Tex/LaTex] Tikz drawing with function

tikz-pgf

I wanna know a clear way to code the function while drawing with it, for ex. how to write this f(x)= -(x+1)(x-2)(x-4)

how to code it in the below command?

\draw [red,ultra thick,domain=-1:2,samples=400,latex-latex] plot (\x,---);

Please there is any clear coding way for these cases?

i tried but it in -5(x + 3)(x-1)(x-2)(x-7) but it didn't work

please wanna coding way for the functions like sin(x) or tan(x)

Best Answer

\documentclass[a4paper]{article}
 \usepackage{tikz}


\begin{document}
\begin{tikzpicture}
\draw[very thin,color=black] (-0,-0) grid (4,4);

\draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
\draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};

\draw[blue] (0,0) plot[domain=2:4] (\x,{-(\x+1)*(\x-2)*(\x-4)}) node[anchor=south west] {$V_{p}$};


\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] Drawing a square with colored hatched little subsquares

With PSTricks just for fun! The remaining tedious parts can be easily added by yourself.

\documentclass[pstricks,border=12pt]{standalone}
\usepackage{pst-node}
\addtopsstyle{gridstyle}{gridlabels=0pt,strokeopacity=.25}

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        hatchcolor=blue,
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        (3,1)
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enter image description here

update

here is my response to barbara beeton's comment:

enter image description here

[Tex/LaTex] Drawing arrows along a function in pgfplots

As you didn't answer my comment yet, I will just post my solution to the problem I think you are trying to solve.

You may just use the code, given in my answer to this question: Add arrows to a smooth tikz function Next you will need to remove the smooth statement, because it will interfere with decorate and give you nice errors like ? Dimension too large. This won't have an effect on the smoothness of your drawing, because you already use sufficiently many samples.

Implementation

\documentclass[border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\tikzset{
  set arrow inside/.code={\pgfqkeys{/tikz/arrow inside}{#1}},
  set arrow inside={end/.initial=>, opt/.initial=},
  /pgf/decoration/Mark/.style={
    mark/.expanded=at position #1 with
    {
      \noexpand\arrow[\pgfkeysvalueof{/tikz/arrow inside/opt}]{\pgfkeysvalueof{/tikz/arrow inside/end}}
    }
  },
  arrow inside/.style 2 args={
    set arrow inside={#1},
    postaction={
      decorate,decoration={
        markings,Mark/.list={#2}
      }
    }
  },
}
\begin{document}
\begin{tikzpicture}
  \draw node [circle] at (-1,0) {$z_0$};
  \begin{scope}[very thick,rotate=45]
    \draw[domain=0:6.28,samples=200] plot (xy polar cs:angle=\x r,radius={1-sin(2*\x r)}) [arrow inside={}{0.25,0.5,0.75}];
  \end{scope}
\end{tikzpicture} 
\end{document}