00:03
So if a and l are constant, then a prime and l -prime equals 0.
00:10
So we have 0 equals 2a minus 0 .01 al, and then we have 0 equals negative 0 .5l plus 0 .001 al.
00:31
And that goes to 0 equals a times 2 minus 0 .01l, and 0 equals l times negative 0 .5 plus 0 .01a.
00:48
For part b, we have dl over d -a is equal to dl dt over d -a over d -a dt, and that is negative 0 .5ls plus 0 .001a.
01:08
Divided by 2a minus 0 .01al.
01:15
For part c, the solution curves are all closed curves that have the equilibrium point point.
01:46
5 ,200 inside them.
01:55
For part d, we have at p .0, 1 ,200, and 200, d -a, d -t is equal to 0, and d -l over d -t is equal to negative 80, which is less, than zero.
02:26
So the number of ladybugs is decreasing and is going in the counterclockwise direction.
03:00
And at p1 equals 5 ,100, the ladybug population.
03:22
Increases dramatically with a maximum of p2, 14, 250, and 200...