Answer:
y = (1/4) 2^x
Explanation:
Remark
y = a * x^n is the general equation. Let's see what that means.
Solution
Solve for x
t_12 = a x^12
1024 = a x^12
t_8 = a x^8
64 = a x^8
Now divide the two equations.
1024/64 = a x^12/a x^8 Cancel out the as
1024 / 64 = x^12 / x^8
16 = x^(12 - 8)
16 = x^4 Take the 4th root of both sides.
=
x = 2
Go back and solve for a
y_12 = a x^12
1024 = a 2^12
1024 = a 4096 Divide by 4096
1024 / 4096 = a
a = 1/4
Problem 7
a) First of negative numbers are probably not a good idea. It means that the population is going to decrease. That's not what will happen if you take care of the fruit flies.
So for the domain, 0 is a good starting point.
That will give you 100 flies on day 0. That's how many you bought.
I'm not a biologist so I have no idea in the world how long a fruit fly will live even with the best of care. I'm going to try 60 days and see what happens.
y = 100 * 1.05 ^60
y = 100 * 18.68
y = 1868
Is this number reasonable? Even with the biggest olive jar you can find, and the best care, I don't think that number is realistic. It's too large. Eventually all will die of disease because they are living in their own waste. So Let's try 20 days
y = 100 * 1.05^20
y = 100 * 2.65
y = 265
That's a lot more reasonable. So for convenience sake let us say that 265 flies could live for 20 days
So to answer the question
The domain would be 0 to 20
The range would be 100 to 265
b)
2 weeks = 2*7 days
2 weeks = 14 days
y = 100 * 1.05^14
y = 100 * 1.98
y = 198 fruit flies.