Q:

N(t) = 25t + 150 for 0<=t<6, (200 + 80t)/(2 + 0.05t) for t>=8The number of fish in a pond at time t years is modeled by the function N defined above, where f is a continuous function such that f(0)=80.a) Find limt→[infinity]N(t). Explain the meaning of limt→[infinity]N(t) in the context of the problem.

Accepted Solution

A:
Answer:1600. This is a maximum limit of fish the pond can host.Step-by-step explanation:For [tex]\lim_{t \to \infty} N(t)[/tex], we must take the part of this function valid for high values, i.e., the second part, where [tex]t \geq 8\\[/tex].[tex]\lim_{t \to \infty} N(t)=\lim_{t \to \infty} \frac{200+80t}{2+0.05t}[/tex]Since we have two polynoms both in numerator and denominator, and both of them are of degree 1 (both linear), for high values of [tex]t[/tex], the main part of each polynom shall be the linear part, neglecting lower degree parts (in this case, constant terms):[tex]\lim_{t \to \infty} \frac{200+80t}{2+0.05t}=\lim_{t \to \infty} \frac{80t}{0.05t}=\frac{80}{0.05} = 1600[/tex]This means that the number of fish in a pond has an horizontal asymthote. In other words, there seems to be a natural limit for the number of fish that there will be in the pond as years pass. The maximum number of fish is actually 1600. With this function, no higher than this figure can be reached. This might imply limits in productivity.