Answer:
The rabbit population will reach its peak after 10 years.
Step-by-step explanation:
Suppose we have a quadratic function in the following format:
[tex]p(t) = at^{2} + bt + c[/tex]
The vertex of the function is the point:
[tex](t_{v}, p(t_{v})[/tex]
In which
[tex]t_{v} = -\frac{b}{2a}[/tex]
If a is negative, the vertex is a peak.
In this question:
[tex]p(t) = -4t^{2} + 80t + 1200[/tex]
So
[tex]a = -4, b = 80, c = 1200[/tex]
According to this quadratic function, after how many years will the rabbit population reach its peak
This is [tex]t_{v}[/tex]
[tex]t_{v} = -\frac{b}{2a} = -\frac{80}{2*(-4)} = 10[/tex]
The rabbit population will reach its peak after 10 years.