Mixed Practice
What is the formula if the y intercept is 13 and the constant multiplier is 3 for an exponential function?
f(x) = 13(3)^x
If f(x) = 10(2)^x then which of the following represents the value of f(0) ?
1. 1 2. 0
3. 10 4. 20
(3) 10
Which of the following is the equation of an increasing exponential function?
1) y = 4(0.75)^x 2) y = 7(3/2)^x
3) y = 5x - 2 4) y = 3x^2
2) y = 7(3/2)^x
You buy a car for $10,000. It loses value at a rate of 34% per year. Write a model to represent the car's value over time.
What is y = 10,000(0.66)t?
Fill in the blanks: A linear function ____________ or ____________ by the same amount. An exponential function ____________ or ______________ by the same amount.
add/subtracts multiplies/divides
What is the formula for an exponential function if the y intercept is 8 and the constant multiplier is .5?
3) y = 8(0.5)^x
Given the function f(x)= (3)(0.5)^x Evaluate the function when x = -4
f(-4) = 48
Describe an exponential growth function.
The ratio is greater than 1.
You buy a car for $10,000. It loses value at a rate of 34% per year. How much value will the car loose in 1 year?
$3400.
Describe the linear function with a negative rate of change.
A line that is decreasing.
What is the formula for an exponential function with a y intercept of 275 and an increase of 7.5%?
4) P = 275(1.075)^h
The value in dollars, v(x), of a certain car after x years is represented by the equation v(x) = 25,000(0.86)^x. To the nearest dollar, how much is the car worth after four years. 1) 2,589 2) 6,510 3) 13,675 4) 18,490
3) 13,675
The equation A = 1300(1.02)^7 is being used to calculate the amount of money in a savings account. What does 1.02 represent in this equation?
1. 0.02% decay 2. 0.02% growth
3. 2% decay 4. 2% growth
4. 2% growth
You buy a car for $15,000. It loses value at a rate of 17% per year. Write a model to represent the car's value over time.
What is y = 15000(0.83)t?
What is a and b in an exponential function?
a = y intercept b = ratio
Growth Rate = 1.35 Initial Amount = 9.8
y = 9.8(1.35)^t What is the growth rate and initial amount?
Describe an decay function.
It's an exponential function that is decreasing.
You deposit $500 in a bank account with a 7% interest rate that is compounded yearly. How much money will you have in your account in 7 years, rounded to the nearest cent.
$802.89
For a recently released movie, the function y = 119.67(0.61)^x models the revenue earned, y, in millions of dollars each week, x, for several weeks after its release. Based on the equation, how much more money, in millions of dollars, was earned in revenue for week 3 than for week 5? 1) 37.27 2) 27.16 3) 17.06 4) 10.11
3. 17.06
If you were to explain to a friend in Algebra class the major difference between a linear and exponential function, what would you say to them?
Linear functions have a CONSTANT RATE OF CHANGE, while exponential functions have a constant MULTIPLYING FACTOR.
what is an asymptote?
What is a line that approaches but doesn't touch the line.
The value in dollars, v(x), of a certain car after x years is represented by the equation v(x) = 25,000(0.86)^x . To the nearest dollar, how much more is the car worth after 2 years than after 3 years? 1) 2,589 2) 6,510 3) 15,901 4) 18,490
1) 2,589
What if a word problem is exponential decay and the percent is 34%. What decimal goes into the formula?
.66
Is this an exponential growth or decay function? What is the growth or decay factor? y = 112(2/3)t?
Decay and the decay factor is (2/3)
If the rate of change is x<1, then what kind of function do you have? Be very specific.
It's an exponential function with decay.