b=0; c=0.02; f=u(1+c-u)^2; g=r(1-u); f1=D[f,u]; g1=D[g,u]; r1=r /. Solve[{f==g,f1==g1},{u,r}][[2]]; r2=r /. Solve[{f==g,f1==g1},{u,r}][[3]]; (*Achtung: Reihenfolge der Lösungen in Mathematika-Versionen unterschiedlich!*) pl=Plot[{f,r1*(1-u),r2*(1-u)},{u,-0.2,1.2},AxesLabel->{"u","f,g"}, ImageSize->{400,300}]; d1=r2/8; d2=(r1+r2)/8; d3=1.2*r1/4; max=2*r1; a1 = a /. Solve[{(1+d1/a)^2*a==max},a]; a2 = a /. Solve[{(1+d2/a)^2*a==max},a]; a3 = a /. Solve[{(1+d3/a)^2*a==max},a]; d:=d1; k1:=-2(1+c); k2:=(1+c)^2+(E^a+d)^2/E^a+b(E^a+d)^2/((E^a)^2); k3:=-(E^a+d)^2/E^a; w1[a_]:= u /. Solve[u^3 + k1 u^2 + k2 u +k3 == 0, u][[1]]; w2[a_]:= u /. Solve[u^3 + k1 u^2 + k2 u +k3 == 0, u][[2]]; w3[a_]:= u /. Solve[u^3 + k1 u^2 + k2 u +k3 == 0, u][[3]]; (*abb=Plot[Evaluate[{w1[a],w2[a],w3[a]}],{a,Log[a1[[1]]]*1.25,Log[a1[[2]]]*0.62}, PlotPoints->2500, AxesLabel->{"log a","u^*"},ImageSize->{400,300}]; *) abb=Plot[Evaluate[{w1[a],w2[a],w3[a]}],{a,Log[a1[[1]]],Log[a1[[2]]]}, PlotPoints->2500, AxesLabel->{"log a","u^*"},ImageSize->{400,300}];