Answer: Third option is correct.
Step-by-step explanation:
Since we have given that
![f(x)=\frac{20}{1+9e^{-3x}}](https://tex.z-dn.net/?f=f%28x%29%3D%5Cfrac%7B20%7D%7B1%2B9e%5E%7B-3x%7D%7D)
As we know that it is a logistic function, and there are two types of growth rate :
1) Increasing Growth rate .
2)Diminishing Growth rate .
Here, Carrying capacity = 20
So, at half of its carrying capacity growth rate changes.i.e.
at y>10, there is diminishing growth rate.
AT y<10, there is increasing growth rate.
so, put y=10
so, it becomes,
![10=\frac{20}{1+9e^{-3x}}\\\\1+9e^{-3x}=\frac{20}{10}=2\\\\9e^{-3x}=2-1\\\\9e^{-3x}=1\\\\e^{-3x}=\frac{1}{9}\\\\\text{Taking logrithms on both sides,}\\\\-3x=\ln 1-\ln9\\\\-3x=-\ln 9\\\\3x=\ln 9\\\\x=\frac{\ln 9}{3}](https://tex.z-dn.net/?f=10%3D%5Cfrac%7B20%7D%7B1%2B9e%5E%7B-3x%7D%7D%5C%5C%5C%5C1%2B9e%5E%7B-3x%7D%3D%5Cfrac%7B20%7D%7B10%7D%3D2%5C%5C%5C%5C9e%5E%7B-3x%7D%3D2-1%5C%5C%5C%5C9e%5E%7B-3x%7D%3D1%5C%5C%5C%5Ce%5E%7B-3x%7D%3D%5Cfrac%7B1%7D%7B9%7D%5C%5C%5C%5C%5Ctext%7BTaking%20logrithms%20on%20both%20sides%2C%7D%5C%5C%5C%5C-3x%3D%5Cln%201-%5Cln9%5C%5C%5C%5C-3x%3D-%5Cln%209%5C%5C%5C%5C3x%3D%5Cln%209%5C%5C%5C%5Cx%3D%5Cfrac%7B%5Cln%209%7D%7B3%7D)
So, the interval will be ![(\frac{ln9}{3},\infty)](https://tex.z-dn.net/?f=%28%5Cfrac%7Bln9%7D%7B3%7D%2C%5Cinfty%29)
Above this there will growth rate at a decreasing rate and below this the growth rate at a increasing rate.
Hence, Third option is correct.
Answer:
£4400
Step-by-step explanation:
5% of 4000 is 200
200*2=400
4000+400=4400
£4400
Answer: I think B
Step-by-step explanation:
I think
Answer
-26+4
Usuahaushbsbwjwjaja
Answer:
<h2> 4(-1+2-3+4-5+6-7+......+1000) = 2000</h2>
Step-by-step explanation:
-1+2 = 1
-3+4 = 1
-5+6 = 1
and so on till -999+1000 = 1
1 .... 1000 - these are 1000 numbers, so
1000:2 = 500 pairs with sum equal 1
4(500•1) = 4•500 = 2000