Bifurcation diagrams of transcritical bifurcation of two normal forms. When the normal forms are continuous dynamical system,  each diagram is drawn by the differential equations 
(Left) dxdtμx−x2{\displaystyle {\frac {dx}{dt}}\mu x-x^{2}}
(Right) dxdt=μx+x2{\displaystyle {\frac {dx}{dt}}=\mu x+x^{2}}.When the normal forms are discrete dynamical system,  each diagram is drawn by the differential equations 

(Left) x↦x+μx−x2{\displaystyle x\mapsto x+\mu x-x^{2}}
(Right) x↦x+μx+x2{\displaystyle x\mapsto x+\mu x+x^{2}}.
Own work
Yapparina