Question

Alana wants to start a chain of emails, which she does by sending an email to 5 of her friends. She asks each of them to send that email to 2 of their friends the next day and to tell each of their friends to send the email to 2 of their friends the day after, and so on. Should the number of people that receive an email each day be modeled with a linear function or an exponential function? Justify your answer and then write an equation to model the situation.

Answer 1

It will be a exponential function. 
here number of mails sent to friends everyday is increasing like 5,10,20,40..... ans so on.
Hence if take out 5 as a common factor then we will get a exponential function.
5(2^0 , 2^1 , 2^2 , 2^3..... so on).

we can write it as 5 (2^x) where x is Whole number.