00:03
All right.
00:05
So we are talking about the population of rabbits, and the population is given to us with the function p of t equals 120t minus 0 .4t to the 4th plus 1 ,000, where t is the time in months since they started the observation.
00:34
So, t equals the time measured in months, and p of t represents the population.
00:50
We want to know two things.
00:51
We want to know when the population is going to be at its max, and when the population will be equal to zero.
01:01
So we have to look at it and examine the graph of this thing.
01:06
So the easiest way to do this, i think, will be to use.
01:10
A graphing utility.
01:12
So if we, in this case, use dezemos graphing, we can type in a function y equals 120x minus 0 .4x to the fourth plus 1 ,000.
01:41
Now, notice, this doesn't really show us what we want to see, right? it looks like we have a zero over here.
01:48
In fact, we can see where we have a zero.
01:49
So it's before 10, but i can't see the y intercept at all.
01:54
So we're going to have to zoom way, way, way, way out...