Phase Portrait

> DOMAIN := t = 0 .. 2 ; # specify reasonable interval for indep vars

> WINDOW := x = 0 .. 10,

> y = 0 .. 5 ; # specify reasonable intervals for all dependent vars

>

> PHASEplot := DEplot( MODEL, VAR, DOMAIN, [ IC ], WINDOW,

> arrows=SLIM,

> scene=[ x, y ], linecolor=BLUE,

> title = `Phase Portrait for # 19(d)` ):

> PHASEplot;

>