p1=Plot[Tanh[x],{x,-3,3},AxesLabel->{"x","y"},ImageSize->{400,300}];
p2=Plot[Coth[x],{x,-3,3},PlotStyle->Dashing[{0.01}],ImageSize->{400,300}];
bild=Show[p1,p2,PlotRange->{-3,3},ImageSize->{400,300}];