> with(DEtools);;
> dfieldplot(diff(y(t), t) = `+`(9.8, `-`(`*`(`/`(1, 5), `*`(y(t))))), y(t), .. 3, y = -3 .. 80, title = `Restricted domain`, color = `+`(9.8, `-`(`*`(`/`(1, 5), `*`(y)))))dfieldplot(diff(y(t), t) = `+`(9.8, `-`(`*`(`/`(1, 5), `*`(y(t))))), y(t), t = -3 .. 3, y = -3 .. 80, title = `Restricted domain`, color = `+`(9.8, `-`(`*`(`/`(1, 5), `*`(y)))))
 

Plot_2d
 

> dfieldplot(diff(y(t), t) = `+`(9.8, `*`(`/`(1, 5), `*`(y(t)))), y(t), t = -3 .. 3, y = -80 .. 10, title = `Restricted domain`, color = `+`(9.8, `*`(`/`(1, 5), `*`(y))))dfieldplot(diff(y(t), t) = `+`(9.8, `*`(`/`(1, 5), `*`(y(t)))), y(t), t = -3 .. 3, y = -80 .. 10, title = `Restricted domain`, color = `+`(9.8, `*`(`/`(1, 5), `*`(y))))
 

Plot_2d
 

> dfieldplot(diff(y(t), t) = `*`(`+`(y(t), 2), `*`(`+`(y(t), `-`(1)))), y(t), t = -3 .. 3, y = -4 .. 2, color = `*`(`+`(y(t), 2), `*`(`+`(y(t), `-`(1)))))dfieldplot(diff(y(t), t) = `*`(`+`(y(t), 2), `*`(`+`(y(t), `-`(1)))), y(t), t = -3 .. 3, y = -4 .. 2, color = `*`(`+`(y(t), 2), `*`(`+`(y(t), `-`(1)))))
 

Plot_2d
 

> dfieldplot(diff(y(t), t) = `+`(ln(t), y(t)), y(t), t = .1 .. 3, y = -3 .. 2, color = `+`(ln(t), y(t)))
 

Plot_2d
 

>