 There is a way to make the custom graphs in Vensim, remember we draw three graphs in our on the paper, over time graph is by default Vensim gives it to us, so no problem. But then the next two graphs was a rate level graph and then effective rebirth rate over P by C ratio graph, so we want to visualize that, so to do that we can create custom graphs in Vensim, I have already created two custom graphs for you, so to see that on the right top there will be something called as control panel in the menu bar, you just observe it for me it is right here, wherever I am moving the mouse you can see it, there will be a control panel, so you click that and you will get a control panel with various things, on that you click graphs and then there is a rate level written there, so just double click it, maybe I will use the opportunity to create one. So, once you come to the graph, click new, name, x axis we want the level, so I am skipping all the thing I have just went to the graphs click new and for the name let us call it rate level graph, let us type it as rate level graph in the name, in x axis let us select click cell, SEL and select population P that is the x axis we want, we want to make the rate level graph, click ok, so you should get it this, leave everything else this default then come here, so this area allows you to select multiple values, so that you can plot multiple graphs over it, but we want only one, so in the first row select click cell and click that net birth rate, click ok, so only three things are entered, rate level graph has a name x axis population P and here it says net birth rate that is it, once you do that you just click ok and you should have an entry called as rate level graph, so you double click it, you will see this graph, the same hum shape graph we saw two minutes ago, that we drew is the exact same graph that you can get here right, in the inflection point is at the population region of 500 which is very apparent here as you can see it is on this graph, instead of checking it over time this makes it easier, so all the graphs that we are trying to do there, we can actually simulate and see we are getting the exact same values and we can check our intuition and actually develop our intuition better, so let us then close this panel come back to this, if we are very simple shape growth with a non-linear system, what happens when P naught is equal to 2000 that is the question, what happens when P naught is equal to 2000, that is your initial value is much higher than your carrying capacity, so what is this behavior we can expect, it will be purely negative feedback system, growth has to there would not be any growth, population has to continuously decline until it reaches the carrying capacity, so it will be a goal seeking behavior, so let us click f of x, click population P change initial value to 2000, click ok, run the model again, yes then click population, click process graph and you can see the same goal seeking behavior that has occurred, same questions on this, why it occurred, the answer is here as an trade is positive or rather as a stock increases up to the value when P by C up to the carrying capacity, we can we get a value in all positive direction, so you expected a growth whether asymptotic growth or exponential growth, but as a value goes higher, so we are doing 1 minus P by C, so this becomes negative, so because of this line, so this becomes your stable equilibrium and this point here is your unstable equilibrium, rather actually it is 0.0, it is unstable equilibrium, population is 0, it is there as long as population becomes 1, it becomes it starts to change, so unstable behavior is at 0.0, so 0, this is stable equilibrium, so goal will be approached in this direction or in this direction, so if this direction you get a goal seeking behavior only, but if the starting point is anywhere here, you are going to get exponential growth, if starting point is anywhere here, suppose the initial value of stock was 9000, 900, carrying capacity is 1000, initial value is 900, then also you will get a goal seeking behavior only, you will not observe a exponential growth within the system, you can try it, we have done this as well as tried the custom graphs, what happens if you notice 2000, we have checked it, so anywhere close to that stable equilibrium point, it is going to only exhibit a goal seeking behavior.