a. Find the exponential function that models the data.
b. According to the model, in which year were there 400 million cellphone subscribers in the United States?
Given Data:
The exponential growth model is
In 2000 the number of telephone users was 110 million.
In 2010 the number of telephone users was 303 million.
Taking 2000 as the base year (t=0) and A as the number of cellphone users then, boundary condition can be written as,
Substituting the boundary condition in the model equation,
101 million
303 million
303 million = 110 million
Thus, the required model equation is,
The time after which the telephone users will be 400 million can be determined as,
Thus, the year in which the number of telephone users will be 400 million is
Thus, in the year 2013 the number of telephone users will be 400 million.
The exponential models describe the population of the indicated country, A, in millions, t years after 2010.Which country has the greatest growth rate? By what percentage is the population of that country increasing each year?
India,
Iraq,
Japan,
Russia,
The burial cloth of an Egyptian mummy is estimated to contain 560 g of the radioactive materialcarbon-14, which has a half life of 5730 years.
a. Complete the table below. Make sure you justify your answer by showing all the steps.
b. Find an exponential function that models the amount of carbon-14 in the cloth, y, after t years. Make sure you justify your answer by showing all the steps.
c. If the burial cloth is estimated to contain 49.5% of the original amount of carbon-14, how long ago was the mummy buried. Give exact answer. Make sure you justify your answer by showing all the steps.