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Differential EquationsChallengeExistence, Uniqueness & Bifurcations

Existence, Uniqueness & Bifurcations · Challenge problem

Near r=1r = 1 the family y′=rln⁡(1+y)−yy' = r\ln(1 + y) - y (for y>−1y > -1) has a transcritical bifurcation at y=0y = 0: besides y=0y = 0 there is an equilibrium y∗(r)y^*(r) with y∗(1)=0y^*(1) = 0. Find lim⁡r→1y∗(r)r−1\displaystyle\lim_{r\to 1}\dfrac{y^*(r)}{r - 1}.