Answer:
The insect population after 6 days is of 1639 insects.
Step-by-step explanation:
A population of insects increases at a rate 230 + 8t + 0.9t2 insects per day
This means that ![r(t) = 230 + 8t + 0.9t^2](https://tex.z-dn.net/?f=r%28t%29%20%3D%20230%20%2B%208t%20%2B%200.9t%5E2)
The population of insects after x days is given by:
![P(t) = \int_{0}^{x}r(t)dt](https://tex.z-dn.net/?f=P%28t%29%20%3D%20%5Cint_%7B0%7D%5E%7Bx%7Dr%28t%29dt)
So
![P(x) = \int_{0}^{x} (230 + 8t + 0.9t^2)](https://tex.z-dn.net/?f=P%28x%29%20%3D%20%5Cint_%7B0%7D%5E%7Bx%7D%20%28230%20%2B%208t%20%2B%200.9t%5E2%29)
![P(x) = 230t + 4t^2 + 0.3t^3 + K|_{0}^{x}](https://tex.z-dn.net/?f=P%28x%29%20%3D%20230t%20%2B%204t%5E2%20%2B%200.3t%5E3%20%2B%20K%7C_%7B0%7D%5E%7Bx%7D)
![P(x) = 230x + 4x^2 + 0.3x^3 + K](https://tex.z-dn.net/?f=P%28x%29%20%3D%20230x%20%2B%204x%5E2%20%2B%200.3x%5E3%20%2B%20K)
In which K is the initital population(which is 50). So
![P(x) = 230x + 4x^2 + 0.3x^3 + 50](https://tex.z-dn.net/?f=P%28x%29%20%3D%20230x%20%2B%204x%5E2%20%2B%200.3x%5E3%20%2B%2050)
After 6 days:
![P(6) = 230*6 + 4*6^2 + 0.3*6^3 + 50 = 1638.8](https://tex.z-dn.net/?f=P%286%29%20%3D%20230%2A6%20%2B%204%2A6%5E2%20%2B%200.3%2A6%5E3%20%2B%2050%20%3D%201638.8)
Rounding to the nearest insect, 1639
The insect population after 6 days is of 1639 insects.