Exponential Functions Growth Decay Compound

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=5000x^x

Give the rate of decay:
y = 35(0.65)^x

• 35%

• 65%

• .35%

• 165%

Give the rate of growth:
y = 5(1.27)^x

• 127%

• 27%

• 5

What is a, the starting term, for the function: f(x) = 800(0.85)^x?

• 800

• 0.85

• 0.15

• x

A population of fish starts at 8,000 and decreases by 6% per year. What is the population of fish after 10 years?

• 14327

• 4309

• 839

• 7680

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

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

What does the a in y=a(1+r)^x  represent?

• Time

• Rate

• Slope

• Initial Amount

Is this exponential growth or decay?

• Growth

• Decay

Your 6 year investment of $40,000 at 14% interest compounded annually is worth how much now?

• $47,798.90

• $87,798.90

• $127,798

• $7,798