The Louisiana black bear was once on the endangered species list. It was thought that as few as 150 bears remained in the wild. Because of conservationists, the population has been increasing. Assuming the population has increased at a rate of approximately 5.3percent over the last 30 years, the situation can be modeled by the equation p(t)=150(1.053)t, where p is the population of the Louisiana black bear after t years. Which of the following statements about the key features of the exponential graph for this situation are true?Statement #1: As t increases, p increases slowly at first, then quickly.Statement #2: The y-intercept is greater than 0.Statement #3: There is a vertical asymptote at p=0.Statement #4: As t increases, p increases at a decreasing rate

1 answer

Let's analyze the provided statements about the population growth of the Louisiana black bear modeled by the equation \( p(t) = 150(1.053)^t \).

Statement #1: As t increases, p increases slowly at first, then quickly.

True. This is characteristic of exponential growth. In the initial phases, the growth rate appears linear (growing slowly), but as time goes on, the effect of compounding leads to a much faster increase in population.

Statement #2: The y-intercept is greater than 0.

True. The y-intercept occurs when \( t = 0 \). Substituting into the equation: \[ p(0) = 150(1.053)^0 = 150(1) = 150 \] Thus, the y-intercept is 150, which is greater than 0.

Statement #3: There is a vertical asymptote at p=0.

False. While the function approaches zero as \( t \) approaches negative infinity, exponential growth functions do not possess vertical asymptotes in the same way that rational functions do. This equation represents a population that will increase indefinitely as \( t \) increases, but it does not have a vertical asymptote at \( p=0 \).

Statement #4: As t increases, p increases at a decreasing rate.

False. As described in statement #1, while the initial growth may seem slow, the rate of increase does not decrease; rather, it increases at an increasing rate due to the properties of exponential functions. The growth is compounding, meaning the increases become larger over time.

Summary of the validity of statements:

  • Statement #1: True
  • Statement #2: True
  • Statement #3: False
  • Statement #4: False

Thus, the statements about the graph of the Louisiana black bear population growth are correctly identified, with only statements #1 and #2 being true.