Respuesta :
Given:
The population, P, of six towns with time t in years are given by the following exponential equations:
(i) [tex]P=1000(1.08)^t[/tex]
(ii) [tex]P = 600 (1.12)^2[/tex]
(iii) [tex]P =2500 (0.9)^t[/tex]
(iv) [tex]P=1200 (1.185)^t[/tex]
(v) [tex]P=800 (0.78)^t[/tex]
(vi) [tex]P=2000 (0.99)^t[/tex]
To find:
The town whose population is decreasing the fastest.
Solution:
The general form of an exponential function is:
[tex]P(t)=ab^t[/tex]
Where, a is the initial value, b is the growth or decay factor.
If b>1, then the function is increasing and if 0<b<1, then the function is decreasing.
The values of b for six towns are 1.08, 1.12, 0.9, 1.185, 0.78, 0.99 respectively. The minimum value of b is 0.78, so the population of (v) town [tex]P=800 (0.78)^t[/tex] is decreasing the fastest.
Therefore, the correct option is b.
