Tikz: Setas corretas no final das curvas paramétricas?

Question

\documentclass[11pt]{amsart}
 \usepackage{tikz}
 \begin{document}
\begin{tikzpicture} [scale=4]
\draw[domain=0:0.4, smooth, variable=\t, samples=200, ->] plot({(1/sqrt(2)*(\t-\t^3)},
{(1/sqrt(2)*(\t+\t^3)});
\draw[domain=0:0.4, smooth, variable=\t, samples=200, ->] plot({\t}, {-\t^3});
\end{tikzpicture}
\end{document}

Olá, as setas apontarão apenas para cima no final das minhas curvas paramétricas. Existe uma maneira de consertar isso?

Editar: remover a opção suave corrigiu o problema. Achei que precisava disso por razões óbvias. Obrigado, Jessé!

Answer 1

O extenso teste mostra que remover a smoothopção elimina o problema.

Código

\documentclass[border=10pt]{standalone}%[11pt]{amsart}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture} [scale=4]
\draw[domain=0:0.4, smooth, variable=\t, samples=200, ->] plot({(1/sqrt(2)*(\t-\t^3)},
{(1/sqrt(2)*(\t+\t^3)});
\draw[domain=0:0.4, smooth, variable=\t, samples=200, ->] plot({\t}, {-\t^3});
\end{tikzpicture}
\begin{tikzpicture} [scale=4]
\draw[domain=0:0.4, variable=\t, samples=200, ->] plot({(1/sqrt(2)*(\t-\t^3)},
{(1/sqrt(2)*(\t+\t^3)});
\draw[domain=0:0.4, variable=\t, samples=200, ->] plot({\t}, {-\t^3});
\end{tikzpicture}
\end{document}