Paper 3 May/June 2004 MATHEMATICH (9709/3) A Levels
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

The number of birds of a certain species in a forested region is recorded over several years. At time $t$ years, the number of birds is $N$, where $N$ is treated as a continuous variable. The variation in the number of birds is modelled by
$\frac{{dN}}{{dt}} = \frac{{N\left( {1800 - N} \right)}}{{3600}}$.
It is given that $N = 300$ when $t = 0$.
a) Find an expression for $N$ in terms of $t$.
b) According to the model,…