Evaluating Piecewise Functions and Exponential Growth and Decay

In an exponential function, what does the 'a' represent? 

• SLOPE
• RATE OF CHANGE
• Y-INTERCEPT
• COMMON RATIO

f(3) =

• -2

• -1

• 0

• 1

• 2

Which of the following functions shows an initial amount of $75 and a decrease of 12% each year?

• y = 75(12)^x

• y = 75(1 + 0.12)^x

• y = 75(0.88)^x

• y = 75(88)^x

f(3) =

• 1

• 9

• 5

• undefined

Determine if the graph represents growth or decay. Also determine the y-intercept.

• decay, 5

• decay, 1

• growth, 5

• growth, 1

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x
• y=30(5000)^x
• y=5000(1.3)^x
• y=5000(0.3)^x

What is the y-intercept of the function?

• 2
• 3
• 1
• -2

Is this exponential growth or decay?

• Growth
• Decay

What is the equation that represents the exponential function in the image below?

• y=3(½)^x
• y=3(2)^x
• y=(2)^x
• y=2(3)^x

f(-1) =

• -2

• -1

• 0

• 1

• 2