Exponential Functions

Which of the following is an exponential function?

• y = x²

• f(x) = 3x³

• y = x³

• f(x) = 3^x

What is the y-intercept in y=4(2)^x

• (4,0)

• (0,2)

• x

• (0,4)

• (4,2)

What is the starting amount in the problem below?

f(t) = 300(1.05)^t

• 300

• 1.05

• t

• y

What is the growth rate in the problem below?

f(t) = 300(1.05)^t

• 300

• 1.05

• t

• y

Describe this function.

• Exponential Growth

• Exponential Decay

• Linear Positive

Mathematical Equivalence

ON

The function y = 125(1.13)^x represents Mr. Gantz's recent investments where x is measured in years.  Which is NOT true?

• Mr. Gantz initial invested $125
• Mr. Gantz's money grows by 13% per year
• After 4 years Mr. Gantz will have about $203.81
• Mr. Gantz earns more money in year one than in year 5

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth
• Decay

Which equation is represented by the table?

• y = 40(2)^x

• y = 40(1/2)^x

• y = 40 - 2x

• y = 40 - 1/2x