各位朋友，
这是我的 MWE。我需要绘制一个旋转不止一圈的三角螺旋线。如何在螺旋线与末端相交处放置箭头？
\begin{tikzpicture}[scale=1.5, cap=round, color = blue];
\draw [->] [thick, domain= 0 : 25. 90, variable=\t,smooth,samples=500] plot ({\t r}: {0.001 *\t*\t} );
\centring
\draw[blue,very thick] (0,0)--(45:1cm) node[right]{};
\draw[blue] (1,1) node{};
\draw (45: 2cm) node{$\bullet$};
\draw [blue, thick](0,0) --(1.4142,0)node[below]{};
\draw[blue, thick](1.4142,0)--(1.4142,1.4142);
\draw( 30: 7 mm) node [ right] {$A$};
%nodes
\node at (0.7071, 0.7071)[ above left] {$\sqrt2$};
\node at (0.7071, 0)[ below ] {$1$};
\node at (1.4142, 0.7071) [ right ] {$1$};
% axis
\draw[->] [blue, thick](0,0)--(2,0) node [right] {$x$};
\draw[->] [blue, thick](0,0) --(0,2) node [right] {$y$};
\draw[-] [blue, ultra thick]( 0,0) --( 1.4142,0){};
\draw[-] [blue, ultra thick]( 0,0) --( 1.4142,1.4142 ){};
\draw( 0,0) node [below left] {};
\end{tikzpicture}