Exponential Function Models Growth and Decay

In March, 2020, before the Covid-19 lockdown, 1,200,000 Texans had applied for unemployment. During the COVID-19 lockdown, the number of people applying for unemployment increased by 4% each month. What exponential function can be used to find the number of people applying for unemployment after x months of COVID-19 lockdown?​

Which of the following exponential functions represents an initial value of 1450 and a decay of 18% for x years?

Which of the following exponential functions represents an initial value of 1780 and a growth of 18% for x years?​

The current population of India (2021) is 1.393 billion people, at an annual rate of increase of 97%. Which exponential function models the population, in billions of people, of India after x number of years?​

A flea medicine breaks down at a rate of 20% per hour. This is the rate of decay of the medicine. The initial dose is 60 milligrams. Which of the following represent the equation the models the amount of flea medicine left in an animal?

Select all the equations that represent exponential decay.

Is this exponential growth or decay?

• Growth

• Decay

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x

• y=30(5000)^x

• y=5000(1.3)^x

• y=5000x^x

What is the pattern you see in this table?

• Common Ratio = 1/3

• Common Difference = 8

• Common Ratio = 3

• Common difference = 3

Pick the equation that is exponential decay

• y=2000(0.88)

• y=0.5(1.88)