Exponential Functions
Sara bought a car for 5,000 dollars and the price increases by 10 percent after a year due to popular demand. Which equation represents this situation?
A) 5,000(1 - 0.001)
B) 5,000(1 + 0.2)
C) 5,000(1 + 0.1)
D) 5,000(1 + 0.01)
C) 5,000(1 + 0.1)
Which two options below do NOT describe a problem that could be solved using an exponential function?
A) You have a starting value of 4 and it triples. Write the equation.
B) A canoe rental service charges a $20 transportation fee plus $30 an hour to rent a canoe. Write an equation.
C) Find the vertex 2x+4x^2+8
D) I buy a house for 100,000 dollars and the price increases by 40% of the current value. Write an equation.
B and C
Which definition is correct for rate of growth?
A) as the x value increases the y value decreases
B) as the x value increases the y value increases
B) as the x value increases the y value increases
Yes or no: does a unique y value repeat more than once in an exponential table?
No the y doesn't not repeat more than once because exponentials are functions
What is the general formula for exponential functions?
A) y = mx + b
B) b/2a
C) (change of y)/(change of x)
D) y = abx
D) y=abx
True or False:
The a in y=ab^x is the starting value
True
What does b represent in y=ab^x?
A) starting value
B) the exponent
C) the rate of growth/decay
C) rate of growth and decay
What does the x represent in y=abx?
A) rate of growth and decay
B) starting value/y intercept
C) the exponent
C) the exponent
Select the exponential expression that best matches the description below.
You have a starting value of 5 and double it x number of times.
A) 3(5)x
B) 5(2)x
C) 2(5)x
D) 5(3)x
B) 5(2)x
Which one is an exponential function?
Function A
x: 0, 1, 2, 3
y: 2, 4, 6, 8
Function B
x: 0, 1, 2, 3
y: 3, 9, 27, 81
Function B
Simplify the equation 400(1 + 0.4)
A) 480
B) 600
C) 560
D) 440
C) 560
Which function is multiplying by 3?
(A) Function A)
x: 0, 1, 2, 3
y: 2, 6, 18, 54
(B) Function B)
x: 0, 1, 2, 3
y: 1/3, 1, 3, 9
(C) all of the above
(C) all of the above
Select the equation that represents the scenario described below.
Sophia buys a motorcycle for 600 dollars and the price depreciates by 50% after one year.
A) 600(.5) = 300
B) 600(1.5) = 900
C) 600(0.05) = 30
A) 600(.5) = 300
True or false:
The line on an exponential graph is called a parabola
False: parabolas are for quadratic functions
Yes or no:
The a in y=ab^x acts as the y-intercept
Yes, because a is the starting value. (Try plugging in 0 for x!)
If the starting value is 6 and it quadruples what is the equation?
A) 4(6)x
B) 6(3)x
C) 2(6)x
D) none of the above
D) none of the above; example answer: 6(4)x
How can you tell a table represents an exponential function? (Choose ALL answers that apply.)
A) the ratio of outputs is a constant
B) the outputs grow by adding the same number each time
C) the outputs are multiplied by the same number each time
D) all of the above
A) the ratio of outputs is a constant
C) the outputs are multiplied by the same number each time
Which word helps you determine whether an amount is getting smaller?
A) increases
B) decay
C) growth
D) rise
B) decay
A house is worth 9,000 dollars and the price increases by 20% in one year. What is the equation that best represents this situation?
A) 9,000(1 - 0.002)
B) 9,000(1 + 0.02)
C) 9,000(1.02)
D) 9,000(1 + 0.2)
D) 9,000(1 + 0.2 )
What is equation for the table below?
x: 1, 2, 3
y: 1/3, 1, 3
(1/3)3x