If you have time try changing the ranges for t in (b) and
(c) to see what happens and why there have to be 3 plots.
5.5(a)
> plot([t/(1+t^4),t^2/(1+t^4),t=-1000..infinity],x=-1..1,-1..1,thickness=5,
scaling=constrained,numpoints=1000,xtickmarks=3,ytickmarks=3,
axesfont=[TIMES,ROMAN,18]);
> plot([t/(1-t^4),(t^2)/(1-t^4),t=1.2..100],x=-1..1,-1..1,thickness=5,
scaling=constrained,numpoints=1000,xtickmarks=3,ytickmarks=3,
axesfont=[TIMES,ROMAN,18]);
> plot([t/(1-t^4),(t^2)/(1-t^4),t=-0.9999..0.9999],x=-1..1,-1..1,
thickness=5,scaling=constrained,numpoints=1000,xtickmarks=3,
ytickmarks=3,axesfont=[TIMES,ROMAN,18]);
> plot([t/(1-t^4),(t^2)/(1-t^4),t=-100..-1.2],x=-1..1,-1..1,thickness=5,
scaling=constrained,numpoints=1000,xtickmarks=3,ytickmarks=3,
axesfont=[TIMES,ROMAN,18]);
> plot([(2*t^2-1)/(1+t^3),t*(2*t^2-1)/(1+t^3),t=-0.99..100],x=-3..3,-3..3,
thickness=5,scaling=constrained,numpoints=10000,xtickmarks=3,
ytickmarks=3,axesfont=[TIMES,ROMAN,18]);
> plot([(2*t^2-1)/(1+t^3),t*(2*t^2-1)/(1+t^3),t=-1000..-1.1],x=-3..3,-3..3,
thickness=5,scaling=constrained,numpoints=1000,xtickmarks=3,
ytickmarks=[-3,0,3],axesfont=[TIMES,ROMAN,18]);
> plot([-(1+t^3)/(1+t^4),t*(1+t^3)/(1+t^4),t=-10000..infinity],
x=-1.5..1,-1..1.5,thickness=5,scaling=constrained,numpoints=1000,
xtickmarks=3,ytickmarks=3,axesfont=[TIMES,ROMAN,18]);