I know that, the function $f(x) = (3*x^2+2*x+7)/(3*x+5)$ has two extrapoints are $(-11/3, -20/3)$ and $(1/3,4/3)$. I use [this answers](https://topanswers.xyz/tex?q=7794) ans tried ``` \documentclass[12pt,a4paper]{article} \usepackage[left=2cm, right=2cm, top=2cm, bottom=2cm]{geometry} \usepackage{fouriernc} \usepackage{pgfplots} \pgfplotsset{compat=1.18 } \usepackage{float} \usepackage{amsmath} \usepackage{amsthm} \begin{document} \begin{figure}[H] \centering \begin{tikzpicture}[>=stealth,scale =1,declare function={a=3;b=2;c=7;d=3;k=5; f(\x)=(a*\x*\x+b*\x+c)/(d*\x+k); g(\x)=b/d - (a* k)/d^2 + (a *\x)/d; x1=(-a* k - sqrt(a*c*d^2 - a *b* d* k + a^2* k^2))/(a* d); x2=(-a*k + sqrt(a*c*d^2 - a*b* d*k + a^2* k^2))/(a*d); xmin=-7;xmax=5;ymin=-8;ymax=3;}] \draw[gray!30] (xmin,ymin) grid (xmax,ymax); \draw[->, thick] (xmin,0)--(xmax,0) node [below left]{$x$}; \draw[->,thick] (0,ymin)--(0,ymax) node [below right]{$y$}; \foreach \X in {x1,x2} {\draw[dashed] (\X,0) |- (0,{f(\X)}); } \node[below right] at (0, 0) {$O$}; \foreach \Y in {x1,x2,0} \fill (\Y,{f(\Y)}) circle(2pt); \foreach \p/\g [evaluate=\p] in {x1/90,x2/180}{% \draw(\p,0)node[shift={(\g:.3)}]{$\p$}; } \foreach \p/\g in {x1/0,x2/180}{% \pgfmathparse{f(\p)} \draw(0,\pgfmathresult)node[shift={(\g:.5)}]{$\fpeval{round(\pgfmathresult,2)}$}; } \clip (xmin,ymin) rectangle (xmax,ymax); \draw[smooth,samples=500,very thick, blue,domain=xmin:10.9] plot(\x,{f(\x)}); \draw[smooth,samples=500,very thick, blue,domain=11.1:xmax] plot(\x,{f(\x)}); \draw[smooth,samples=500,very thick, blue,domain=xmin:xmax]plot(\x,{g(\x)}); \draw[thick, blue] (-k/d,ymin) -- (-k/d,ymax); \fill[red] (-k/d,{-((-b* d + 2 *a *k)/d^2)}) circle(2 pt); \end{tikzpicture} \end{figure} \end{document} ``` and got ![image.png](/image?hash=2c13724fe4e98a7e23f87e156839e8a303273f8f0fb110f1328db0a79c2fd6c6) How can I chang the numbers `-6.67` into `-20/3`, `-3.66666` into `-11/3`, `0.33333` into `1/3` and `1.33` into `4/3`. Can I use this answer to my question? [here](https://tex.stackexchange.com/questions/722475/how-can-i-get-f2-3-20-9-and-f4-3-16-9-of-the-function-fx-3-x3/722615#722615) ``` \documentclass[12pt,a4paper]{article} \usepackage{pgfplots} \usepackage{xintexpr} \ExplSyntaxOn \bool_new:N \l__pgfmathxintexpr_xinteval_bool \tl_new:N \l__pgfmathxintexpr_function_tl \tl_new:N \l__pgfmathxintexpr_parse_tl \cs_new_eq:NN \__pgfmathxintexpr_pgfmath_parse_old:n \pgfmathparse \cs_new_eq:NN \__pgfmathxintexpr_pgfmath_print_number_old:wn \pgfmathprintnumber \pgfkeys { / pgf / declare~xintexpr~function /. code = { \tikzset { declare~function = { #1 ; } } \tl_set:Nn \l__pgfmathxintexpr_function_tl { #1 ) ; } \tl_replace_all:Nnn \l__pgfmathxintexpr_function_tl { \x } { x } \tl_replace_once:Nnn \l__pgfmathxintexpr_function_tl { = } { : = reduce ( } \exp_after:wN \xintdeffunc \l__pgfmathxintexpr_function_tl } , / pgf / number~format / xintexpr /. code = \bool_set:Nn \l__pgfmathxintexpr_xinteval_bool { \cs:w c_#1_bool\cs_end: } , / pgf / number~format / xintexpr /. default = true , / pgf / number~format / xintexpr = false } \RenewDocumentCommand \pgfmathparse { m } { \__pgfmathxintexpr_pgfmath_parse_old:n {#1} \tl_set:Nn \l__pgfmathxintexpr_parse_tl {#1} } \RenewDocumentCommand \pgfmathprintnumber { O {} m } { { \pgfkeys { / pgf / number~format , #1 } \bool_if:NTF \l__pgfmathxintexpr_xinteval_bool { \tl_if_eq:nnTF {#2} { \pgfmathresult } { \xinteval { \l__pgfmathxintexpr_parse_tl } } { \xinteval {#2} } } { \__pgfmathxintexpr_pgfmath_print_number_old:wn [#1] {#2} } } } \ExplSyntaxOff \begin{document} \begin{tikzpicture}[declare xintexpr function={f(\x)=(3*\x*\x+2*\x+7)/(3*\x+5)}] \node at (0,0) {\pgfmathprintnumber[xintexpr]{f(1/3)}}; \node at (0,-1) {$\pgfmathprintnumber[xintexpr]{f(-11/3)}$}; \end{tikzpicture} \end{document} ```