Mrthfx

Does anyone know why this plot looks funny between 0 and 1 ? The same will happen if I try to plot the cube root function. Please advise. I am trying to avoid using pgfplots package.

documentclass{article}

usepackage{tikz}



begin{document}

begin{tikzpicture}[scale=.6,cap=round]

tikzset{axes/.style={}}

  % The graphic

draw[style=help lines,step=1cm, dotted] (-.5,-3.5) grid (10.5,5.5);

begin{scope}[style=axes]

draw[->] (-0.5,0) -- (10.5,0) node[right] {$x$};

draw[->] (0,-3.5) -- (0,5.5) node[above] {$y$};

    foreach x/xtext in {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

draw[xshift=x cm] (0pt,2.6pt) -- (0pt,-2.6pt) node[below,fill=white]

         {scriptsize $xtext$};

foreach y/ytext in {-3, -2, -1,  1, 2, 3, 4, 5}

draw[yshift=y cm] (2.6pt,0pt) -- (-2.6pt,0pt) node[left,fill=white]

        {scriptsize $ytext$};

%filldraw[blue] (0,0) circle (3pt) node[fill=white,below right=12pt] 

{scriptsize $(0,0)$};

filldraw[blue] (1,1) circle (3pt) node[fill=white,above=3pt] {scriptsize 

$(1,1)$};

filldraw[blue] (3,1.732) circle (3pt) node[fill=white,below=3pt] 

 {scriptsize $(3,sqrt{3})$};

filldraw[blue] (4,2) circle (3pt) node[fill=white,above=3pt] {scriptsize 

$(4,2)$};

filldraw[blue] (9,3) circle (3pt) node[fill=white,above=3pt] {scriptsize 

$(9,3)$};

draw[domain=0:10,smooth,variable=x,blue,thick,->] plot ({x},{(x)^.5});

end{scope}

end{tikzpicture}





end{document}

Because your sample is not large enough: by default it is 25 points. With a sample of 200 points, this works.

Edit: Modification of the sample. Many thanks to Skillmon for having the idea to modify the sample and to @marmot for giving a simple and effective example.

Your foreach loops do not need to have two variables. Only one is enough, for the displayed text to be smaller, there is the key font=scriptsize.

Edit 2:
And to avoid repeating this for each node, just do it with every node/.style={font=scriptsize} to overwrite the pre-existing style or every node/append style={font=scriptsize} to simply add this style to the pre-existing style without overwriting it.

documentclass{article}

usepackage{tikz,pgfplots}

begin{document}

begin{tikzpicture}[scale=.6,cap=round,every node/.style={font=scriptsize}]

tikzset{axes/.style={}}

  % The graphic

draw[style=help lines,step=1cm, dotted] (-.5,-3.5) grid (10.5,5.5);

begin{scope}[style=axes]

draw[->] (-0.5,0) -- (10.5,0) node[right] {$x$};

draw[->] (0,-3.5) -- (0,5.5) node[above] {$y$};

    foreach x in {1, ..., 10}

draw[xshift=x cm] (0pt,2.6pt) -- (0pt,-2.6pt) node[below,fill=white]

         { x};

foreach y in {-3,..., 5}

draw[yshift=y cm] (2.6pt,0pt) -- (-2.6pt,0pt) node[left,fill=white]

        { y};



filldraw[blue] (0,0) circle (3pt) node[fill=white,below right=12pt] 

{$(0,0)$};

filldraw[blue] (1,1) circle (3pt) node[fill=white,above=3pt] {

$(1,1)$};

filldraw[blue] (3,1.732) circle (3pt) node[fill=white,below=3pt] 

 {$(3,sqrt{3})$};

filldraw[blue] (4,2) circle (3pt) node[fill=white,above=3pt] {

$(4,2)$};

filldraw[blue] (9,3) circle (3pt) node[fill=white,above=3pt] {

$(9,3)$};

draw[domain=0:10,smooth,variable=x,blue,thick,->,samples at={0,0.05,...,1,1.5,...,10.5}] plot ({x},{(x)^.5});

end{scope}

end{tikzpicture}

end{document}