The heart rate of a person can be modeled by the function r(a)=211−0.64a where a is the person's age in years and r(a) is heartbeats per minute. The life span in minutes of a person is modeled by the function s(a)=525,600a . Explain what (r⋅s)(a) represents. (1 point) Responses
the total number of heartbeats in a lifetime of a person who is a years old
the total number of heartbeats in a lifetime of a person who is a minutes old
the heart rate of a person who is a minutes old
the heart rate of a person who is a years old
The correct response is: the total number of heartbeats in a lifetime of a person who is a years old.
This is because (r⋅s)(a) represents the product of the heart rate function r(a) and the lifespan function s(a), giving us the total number of heartbeats in a person's lifetime. This is calculated by first finding the heart rate at a certain age (r(a)), and then multiplying it by the total lifespan in minutes (s(a)).