Logs
log525
2
Your test grade loses 5% per wrong answer.
Neither
Key point on the parent function (y-intercept)
(0,1)
Key point on the logarithmic function (x-intercept)
(1,0)
A population of field mice is 120. The population increases at a rate of 9% a year. Write an exponential function that models this situation
f(t) = 120(1 + 0.09)t
log381
4
Your bank account gains 2% interest each quarter
Growth
Describe the transformation that took place: y=4x-3
Right 3
Domain of the parent function
(0, infinity)
A painting is valued at $10,000 but the value increases at a rate os 3% a year. How much will the paining be worth in 5 years?
$11592.74
log31
0
y=55(0.96)x
Decay
Describe the transformation that took place: y=2-x
Reflection about y-axis
Describe the transformation: y= log(x-4)
Right 4
The population of wild ducks in Lake County is 2,500. The population is decreasing at a rate of 7% a year. How many ducks will be left in 10 years?
1209 ducks
log3(1/9)
-2
y=90(1+0.3)x
Growth
Describe the transformation that took place: y=4x+5-1
Left 5, down 1
Describe the transformation: y=logx +6
Up 6
The bear population increases at a rate of 2% per year. There are 1,573 bears right now. Write a function that models the bear population. How many bears will there be in 10 years?
In 10 years: 1917
log7710
10
What is the rate of growth or decay?
y=45(0.3)x
Decay rate: 0.7 or 70%
Graph the function y=2(3)x
Make a table!
What is ln called
The natural log
The population of an endangered bird is decreasing at a rate of 1% per year. There are currently only 200,000 of these birds left in the wild. Write a function that models the bird population. How many birds will there be in 100 years?
Function: f(t)=200,000(.99)t
In 100 years, 73,206 birds will be left.