MHB How does the population of a southern city follow the exponential law?

AI Thread Summary
The population of a southern city follows the exponential growth model, expressed as N(t) = N_0e^{kt}. Given that the population doubled in 18 months and is currently 10,000, the growth constant k is approximately 0.462098. Using this value, the projected population in two years is approximately 25,198. A suggestion was made to clarify the equation setup for better understanding, but it was acknowledged as a minor point. The calculations and logic presented were deemed correct overall.
karush
Gold Member
MHB
Messages
3,240
Reaction score
5
$\tiny{\textbf{6.8.7}}$ Kiaser HS

Population Growth The population of a southern city follows the exponential law
(a) If N is the population of the city and t is the time in years, express N as a function of t.$N(t)=N_0e^{kt}$
(b) If the population doubled in size over an 18-month period and the current population is 10,000, what will
the population be 2 years from now?
$\begin{array}{rl}
2&=e^{k(1.5)} \\
\ln 2&=k \cdot 1.5\\
\dfrac{\ln 2}{1.5}&=k\\
\therefore k&\approx0.462098\\
f(t)&\approx10000e^{0.462098\cdot 2}\\
&\approx 25198
\end{array}$

well anyway hopefully ok :unsure:
typos maybe
 
Mathematics news on Phys.org
I didn't check the numbers but the logic is correct.

-Dan
 
Since you stated your basic equation as
$N(t)= N_oe^{kt}$
I would have preferred that you write
$2N_0= N_0e^{1.5k}$
before you divide both sides by $N_0$ to get
$2= e^{1.5k}$.

But I realize that is being petty!
 
Thread 'Video on imaginary numbers and some queries'
Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
Thread 'Unit Circle Double Angle Derivations'
Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...
Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
Back
Top