I would like to have a figure like the following image, but I can't find a way to make the red convex curves.
My code so far contains:
\begin{tikzpicture}
\draw (1, 3.5) to[out=0,in=90] (3.5, 1);
\draw (.5, 3) to[out=0,in=90] (3, .5);
\draw (.25, 2.5) to[out=0,in=90] (2.5, 0.25);
\draw[-, very thick] (0,0) node[below]{O} -- (4.2,0) node[below] {y};
\draw[-, very thick] (0,0) -- (0,4) node[left]{x};
\draw[-,very thick] (0,4)--(4.2, 4) node[above]{A};
\draw[-, very thick] (4.2, 4)--(4.2,0);
\end{tikzpicture}
Best Answer
That should do:
I am sure that there is a much more efficient way of doing it, but this is a starting point.