Let denote the inclusion and denote the projection onto the -axis,
so is the continuous projection of onto the -axis.
Suppose is a continuous path from to .
It follows by the Intermediate value theorem that the image .
Let .
Clearly , for if it were we could find a such that by the intermediate value theorem.
Again invoking the intermediate value theorem,
there exists an increasing sequence such that .
Now (why?), so by sequential continuity.
But is not convergent, since its -coördinate alternates between and ,
a contradiction.
Therefore cannot be a continuous path.