Exponential Growth and Decay Applications

A population of 2200 beetles is too large to sustain and decreases in population each month at a rate of 5%. How would you write your decay factor, b?

• -5

• -.05

• .95

• .05

Classify the model as Exponential GROWTH or DECAY.
A=10(1.01)³

• Growth

• Decay

What is the decay rate in the following model?
A=1200(.85)⁶

• -1200

• -.15

• 6

• -6

What type of function is y = 7(5/4)^x?

• Exponential Growth

• Exponential Decay

• Linear

• None of the above

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(1 - 0.30)^x

• y=30(5000)^x

• y=5000(1 + 0.30)^x

• y=5000x^x

What is a, the starting term, for the function: f(x) = 300(1.16)^x?

• 300

• 1.16

• .16

• x

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 + 0.35)^x

• y = 15(0.35)^x

• y = 35(1+ 0.15)^x

James' 70 in. giant peach doubles in size every week. Write an expression that would represent how big the peach is after 5 weeks.

• 70(2)³⁵

• 70(2)⁵

• 2(70)⁵

• 5(70)²

Write an equation that models the following situation:

Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1+ 0.14)^x

• y=6(1 - 0.14)^x