Graph whit Tikz

Question

I wanto to draw this graph whit Tikz:

I have this code:

\begin{tikzpicture}[scale=0.2]                                                                                          
 \begin{scope}                                                                                                          
% Relleno gris superior e^x                                                                                             
                   clip \fill [color=gray!40, domain=-1.2:1.2, variable=\x]                                             
                   (-1.2, 0)                                                                                            
                   -- plot ({\x}, {exp(\x)})                                                                            
                   -- (-1.2, 3.29) -- cycle;                                                                            
                   % % Relleno blanco inferior de e^-x                                                                  
                   clip \fill [color=white, domain=-1.2:1.2, variable=\x]                                               
                   (-1.2, 0)                                                                                            
                   -- plot ({\x}, {exp(-\x)})                                                                           
                   -- (1.2, 0) -- cycle;                                                                                
                    \end{scope}                                                                                         
                    \begin{scope}                                                                                       
                   % Relleno gris inferior  e^x                                                                         
                   clip \fill [color=gray!40, domain=-1.2:1.2, variable=\x]                                             
                   (-1.2, 0)                                                                                            
                   -- plot ({\x}, {exp(\x)})                                                                            
                   -- (1.2,0) -- cycle;                                                                                 
                   % Relleno blanco inferior de e^-x                                                                    
                   clip \fill [color=white, domain=-1.2:1.2, variable=\x]                                               
                   (-1.2, 3.29)                                                                                         
                   -- plot ({\x}, {exp(-\x)})                                                                           
                   -- (1.2, 3.29) -- cycle;                                                                             
                 \end{scope}                                                                                            
                   % Funciones e^x                                                                                      
                   \draw[-] plot[domain=-1.2:1.2] (\x,{exp(\x)});                                                       
                                      % Funciones e^-x                                                                  
                   \draw[-] plot[domain=-1.2:1.2] (\x,{exp(-\x)});                                                      
                   % coordinate grid                                                                                    
                   \draw[->] (-4,0)--(4,0) node[right]{$x$};                                                            
                   \draw[->] (0,-4)--(0,4) node[above]{$y$};                                                            
                   \draw (0,1) node[ right] {{\tiny $1$}};                                                              
                 \end{tikzpicture}

Is wrong:

Do a search on the site for "fillbetween". You'll find plenty of examples. — JeT, May 17 '20 at 20:17
You can "accept" the provided answer since it seems to solve solve your problem. — Dr. Manuel Kuehner, Sep 08 '20 at 18:55

score 1 · Answer 1 · 2020-05-17T22:51:31.567

Welcome! From your picture I didn't know which of these you want.

\documentclass[tikz,border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[>=stealth,%
    p1/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(\x)})}},
    p2/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(-\x)})}}]
 % fills
 % upper
 \begin{scope}
  \clip[p1] -| cycle;
  \fill[gray!40,p2] |- cycle;
 \end{scope}
 % lower
 \begin{scope}
  \clip[p1] -- (1.2,0) -| cycle;
  \fill[gray!40,p2]  -- (1.2,0) -| cycle;
 \end{scope}
 % plots
 \draw[->] (-4,0)--(4,0) node[right]{$x$};                                                            
 \draw[->] (0,-4)--(0,4) node[above]{$y$};                                                            
 \path (0,1) node[right,font=\tiny] {$1$};        
 \draw[semithick,p1];                                                       
 \draw[semithick,p2];          
\end{tikzpicture}

\begin{tikzpicture}[>=stealth,%
    p1/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(\x)})}},
    p2/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(-\x)})}}]
 % fills
 % upper
 \begin{scope}
  \clip[p1] -| cycle;
  \fill[gray!40,p2] |- cycle;
 \end{scope}
 % lower
 \begin{scope}
  \clip[p1]  |- cycle;
  \fill[gray!40,p2]   -| cycle;
 \end{scope}
 % plots
 \draw[->] (-4,0)--(4,0) node[right]{$x$};                                                            
 \draw[->] (0,-4)--(0,4) node[above]{$y$};                                                            
 \path (0,1) node[right,font=\tiny] {$1$};        
 \draw[semithick,p1];                                                       
 \draw[semithick,p2];          
\end{tikzpicture}
\end{document}

I think this is very similar to what you had in mind but if you use

 clip \fill

the clip does not have any effect. Also it is perhaps simpler to store the paths that get reused in styles like p1 and p2 here.

You actually do not need a clip.

\documentclass[tikz,border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[>=stealth,%
    p1/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(\x)})}},
    p2/.style={insert path={plot[domain=-1.2:1.2] (\x,{exp(-\x)})}}]
 % fill
 \fill[gray!40,p1]  --  plot[domain=-1.2:1.2] (\x,{exp(-\x)});
 % plots
 \draw[->] (-4,0)--(4,0) node[right]{$x$};                                                            
 \draw[->] (0,-4)--(0,4) node[above]{$y$};                                                            
 \path (0,1) node[right,font=\tiny] {$1$};        
 \draw[semithick,p1];                                                       
 \draw[semithick,p2];          
\end{tikzpicture}
\end{document}

The other version works analogously.

Thanks cat, I didn't know that way to fill. Where can I find more information about that? — Arnold Fernández, May 17 '20 at 22:22
@ArnoldFernández Then you have found an old version. The current version of the pgfmanual has 1318 pages. The \fill command is already used on the title page. It may be thought of as a synonym of \path[fill]. Its basic usage is explained in section 2.13 Filling and Drawing. The perhaps more important points of this answer are the clips, the |- and -| syntax, and the insert path key, though. — , May 17 '20 at 22:38

Graph whit Tikz

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