Calculus and the physical world qu (1 Viewer)

[~amy~]

A city doubles its population in 25 years. If it is growing exponentially, when will it triple its population?

 

[smallcattle]

2=1e^25k

find k

then

3=1e^kt

to find t

 

[flyhigh]

2A = Ae^kt
2 = e ^25k
25k = ln2
k = ln2/25

3A = Ae^kt
3 = e^kt
kt = ln3
t = ln3/k ..substituting k from above
t = 39.6 years

 

[Silverstone]

*Gratuitously shows off siggie

 

[~amy~]

Thanks alot