00:01
Hi there, so for this problem, we are given the following differential equation that the population of rabbits, the derivative of that with respect to time, is equal to a concept of proportionality times the population at any given time to the square.
00:22
Now, we are given the information that the initial population of rabbits is five rabbits, and it is increasing at the rate of two rapids per month.
00:34
So we're given that the real change of the population of rabbits with respect to time when the population p is equal to 25, then this is equal to two.
00:51
Now, once we note this, we need to determine which, if any of the following statements is correct.
01:00
So what we need to do first, and with this information in here, we can first determine the value of the concept of proportionality k.
01:10
Because by using this condition, we will have that this is 2 is equal to k.
01:17
This when the population is 25 to the square.
01:22
So that will give us that the constant of proportionality is 2 divided by 25 to the square.
01:30
So that will be 25 to the square is equal to so we will have that that is 2 divided by 625.
01:41
So with that, we will have that now.
01:46
The differential equation is equal to 2 divided by 625, this times the population square.
02:01
Then we can just separate the variable.
02:04
So we will have the differential in the population divided by the population to the square is equal to 2 divided by 625 times the differential in time.
02:18
Now we can integrate both sides of this expression.
02:22
Now for the left side we obtain minus 1 divided by the population.
02:35
Then this is equal to 2 divided by 625, this times the time, this plus a constant of integration, because this is an indefinite integral.
02:54
Now to find the value of c, we can use the initial condition that the population at the time equals to 0 is 5, so we will have minus 1 divided by the population.
03:07
Is equal to c, well, this is when the population is equal to 5, the initial population.
03:21
So from this, we obtain that c, it hits this value, so we will have minus 1 divided by the population is equal to 2 divided by 625 times the time this, minus 1 divided by 5.
03:36
So we can simplify this further, so we will have that this is minus 1 divided by the population is equal to, so we hope that this is 2 times 5, so that will be 10 times the time, this minus 625.
03:58
This divided by 625 times 5, so that will be 3 ,000 ,000, 125.
04:11
We can divide all of these numbers by 5...