If I have M(x) and B(y), where M and B are non-invertible functions (what I am attaching is just an example), how can I plot x vs y for values where the images are equal, i.e., M(x) = B(y)? In the example, I believe the values of x and y should lie within [0, 1.6] approximately for M and B.
You may try ContourPlot:
ContourPlot[M[x] == B[y], {x, 0, 1.1}, {y, 0, 1.1}]
thank you very much