Answer:
Step-by-step explanation:
The question is incomplete. Here is the complete question.
The population of a certain species of bird in a region after t years can be modeled by the function P(t) = 1620/ 1+1.15e-0.42t , where t ≥ 0. When will the population reach 1,200?
According to question we are to calculate the time t that the population P(t) will reach 1200.To do this we will substitute P(t) = 1,200 into the equation and calculate for the time 't'.
Given;
[tex]P(t) = \frac{1620}{1+1.15e^{-0.42t} } \\\\at \ P(t)= 1200;\\\\1200 = \frac{1620}{1+1.15e^{-0.42t} }\\\\cross\ multiplying\\\\1+1.15e^{-0.42t} = \frac{1620}{1200} \\\\1+1.15e^{-0.42t} = 1.35\\\\1.15e^{-0.42t} = 1.35-1\\\\e^{-0.42t} = \frac{0.35}{1.15}\\ \\e^{-0.42t} = 0.3043\\\\Taking \ ln\ of\ both\ sides\\\\lne^{-0.42t} = ln0.3043\\\\-0.42t = -1.1897\\\\t = \frac{-1.1897}{-0.42} \\\\t = 2.8 years\\\\[/tex]
The population will reach 1200 after about 2.8 years
