# Plot two functions on the same plane, $y=f(x)$ and $x=g(y)$

I'm trying to plot two functions. In general, this is not a difficult task, thanks e.g. to the command:

Plot[{Sin[x], Cos[x]}, {x, 0, 2 Pi}, PlotLabels -> "Expressions"]


However, I would like to plot two functions, one of them with respect to variable $$x$$ of the plane, and another with respect to the variable $$y$$. For example $$y=\ln x$$ and $$x=y^2$$.

Someone knows what should I do?

You can use ContourPlot, but then you have to supply the $$y$$-range:
ContourPlot[{y==Log[x], x == y^2}, {x, -2, 2}, {y, -2, 2}, Axes->True, Frame->False]

Both kinds of plots can be thought of as parametric plots, where for the first one $$x$$ is the independent parameter and for the second one $$y$$ is the independent parameter. With ParametricPlot take a parameter $$t$$ that is used in both roles:
f[x_] = Log[x];