Q:

The number of people, n, who know a rumor can be modeled using the equation n(*)=20(2)*, where * is the number of days since Monday. (A) Explain why n(0)=20. What does this represent in terms of the situation modeled? (B) What is the value of n(-2)? What does represent in the situation modeled?

Accepted Solution

A:
Using an exponential function, it is found that:a) n(0) = 20 means that on Monday, 20 people knew about the rumor.b) n(-2) = 5, it means that on the previous Saturday, 5 people knew about the rumor.What is an exponential function?It is modeled by:[tex]y = ab^x[/tex]In which:a is the initial value.b is the rate of change.In this problem, the function is:[tex]n(x) = 20(2)^x[/tex]Item a:Day 0 is referent to Monday, hence n(0) = 20 means that on Monday, 20 people knew about the rumor.Item b:[tex]n(-2) = 20(2)^{-2} = 5[/tex]Since Day 0 is referent to Monday, Day -2 is referent to the previous Saturday, when 5 people knew about the rumor.More can be learned about exponential functions at