This Maple file shows three animations. The first is a nonlinear, undamped pendulum.The second is a competing species model, and the third is a predator-prey model.If you want to have all of them get constructed, press the button above with three exclamation points: !!!To play the animation, click on the plot and a play button will show up under the toolbars above.Eqn1:=diff(x(t),t)=y(t), diff(y(t),t)=-sin(x(t));with(DEtools):DEplot({Eqn1},{x(t),y(t)},t=0..8,x=-10..10,y=-3..3,arrows = comet, animatefield = true, numframes = 50, dirfield = 300);PkkkTFZTRzYiNyQvLUklZGlmZkclKnByb3RlY3RlZEc2JC1JInhHRiQ2I0kidEdGJEYuKiZGKyIiIiwoRjBGMEYrISIiLUkieUdGJEYtRjJGMC8tRig2JEYzRi4qJkYzRjAsKEYrJCEjdiEiIyQiIiZGMkYwRjMkISNERjxGMA==JSFHLUknREVwbG90RzYiNitJJExWU0dGJDckLUkieEdGJDYjSSJ0R0YkLUkieUdGJEYqL0YrOyIiISIjNy9GKTshIiIiIiQvRi1GMy9JJ2Fycm93c0dGJEkmY29tZXRHRiQvSS1hbmltYXRlZmllbGRHRiRJJXRydWVHJSpwcm90ZWN0ZWRHL0kqbnVtZnJhbWVzR0YkIiNdL0kpZGlyZmllbGRHRiQiJCskPkkkTFZTRzYiNyQvLUklZGlmZkclKnByb3RlY3RlZEc2JC1JInhHRiQ2I0kidEdGJEYuKiZGKyIiIiwmRjBGMC1JInlHRiRGLSQhIiYhIiJGMC8tRig2JEYyRi4qJkYyRjAsJkYrJCIjRCEiIyQhI3ZGPkYwRjA=LUklbXJvd0c2Iy9JK21vZHVsZW5hbWVHNiJJLFR5cGVzZXR0aW5nR0koX3N5c2xpYkdGJzYjLUkjbWlHRiQ2I1EhRic=LUknREVwbG90RzYiNitJJExWU0dGJDckLUkieEdGJDYjSSJ0R0YkLUkieUdGJEYqL0YrOyIiISIjNy9GKTtGMCIjNS9GLTtGMCIiJi9JJ2Fycm93c0dGJEkmY29tZXRHRiQvSS1hbmltYXRlZmllbGRHRiRJJXRydWVHJSpwcm90ZWN0ZWRHL0kqbnVtZnJhbWVzR0YkIiNdL0kpZGlyZmllbGRHRiQiJCsk