Here, it turns out that condition (1) can be relaxed slightly, and the left-hand side of (2) has been corrected from the value
of 1 given by Rasband (1990, p. 30).

Then there are two branches, one stable and one unstable. This bifurcation
is called a transcritical bifurcation.

An example of an equation displaying a transcritical bifurcation is