The number of bacteria in an experiment is presently 38,300. Each hour, the cells split, doubling the number of bacteria present. How many millions of bacteria are present after 9 hours?
Approximately 19 million bacteria. (19,609,600)
Use y = 250(1.2)^t What is the initial value?
What is 250
Write an exponential growth function to model the situation. A population of 422,000 doubles each year.
What is f(x) = 422,000(2)^x
Given f(x) = 2(3)x
What is the y-intercept?
(0, 2)
A child puts 1,900 pennies in their piggy bank. Once a week, their brother sneaks in to steal money, leaving only 1/4 of the pennies behind. How many pennies will the poor child be left with after 3 weeks?
29
Use y = 250(1.2)^t What is the multiplier?
What is 1.2
The population of Baconburg starts off at 20,000. Each summer, the swamp monster gets hungry and eats half of them. Write an exponential model.
What is f(10) = 20,000(0.05)^x
Given f(x) = 2(3)x
What is the asymptote?
y = 0
what does x0 equal?
1
Use y = 250(1.2)^t What is the growth rate in percent?
What is 20%
The Hippityhoppity bunny decided to have a family reunion at the Magic Forest every 5 years. During the second reunion the family discovered that the number of family members was 154 and was growing at an annual rate of 3.2%. Write an equation to model the growth of the bunny family.
What is f(x) = 154(1.032)^x
Given f(x) = 2(3)x
What is the domain?
all real numbers
What is the difference between linear and exponential functions, regarding how the y values change?
Linear = repetitive adding
Exponential = repetitive multiplication
y = 9.8(0.35)^t What is the decay rate in percent?
What is 65%
The fish in The Magic Forest Lake were declining at an annual rate at 1.5%. Their current number is estimated at 2500. Write an equation to model the decreasing number of fish.
What is y = 2500(.985)^x
Given f(x) = 2(3)x
What is the range?
y > 0
What happens if you add a value to an exponential function?
For example, y = 3(2)x + 5
shifts the graph up
Given the two points (0, 4) and (1, 1), what is the decay factor (b)?
0.25
The squid in The Magic Forest Lake were declining at an annual rate at 5.5%. Their current number is estimated at 50,000. Write an equation to predict the number of squid in the lake in 10 years.
What is f(10) = 50000(.945)^10 and 28,398 squid
define asymptote
a line that the graph approaches but never touches