Unit 5 Exponential Functions Review

Which graph represent the exponential decay of a radioactive element?

• A

• B

• C

• D

Tags

CCSS.HSF-IF.C.7E

Which of the following is an exponential function?

• $y=3x^2$

• $y=3x-1$

• $y=3^{\left(x-1\right)}$

• $y=\frac{x-2}{3-x}$

Identify all the tables that are exponential functions.

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Tags

CCSS.HSF-LE.A.1A

 $y=4^x$  The graph of this equation is shifted three units to the left and one unit up.  What is the new equation?

•  $y=4^{\left(x+1\right)}-3$  

•  $y=4^{\left(x+3\right)}-1$  

•  $y=4^{\left(x-3\right)}+1$  

•  $y=4^{\left(x+3\right)}+1$  

Tags

CCSS.HSF.BF.B.3

Which of the following equations could represent the graph?

• $y=3^x+2$

• $y=3^x-2$

• $y=3^{\left(x+2\right)}$

• $y=3^{\left(x-2\right)}$

Tags

CCSS.HSF.LE.A.2

 In recent years, the number of students who participate in cheerleading has decreased. The function  

$y=24,200\left(0.986\right)^x$

where y is thousands, and x is the number of years since 2005, models the number of people who are on their high school cheerleading team. Estimate the number of students who are on their high school cheerleading team in 2012.  Round your answer to the nearest whole number.

Jennifer bought a tractor that depreciates at a rate of 7% per year. The tractor costs $52,000. Which equation represents the value of the tractor after 8 years?

• $y=52000\left(0.93\right)^8$

• $y=52000\left(0.07\right)^8$

• $y=52000\left(1.93\right)^8$

• $y=52000\left(1.07\right)^8$

Which equation represents an exponential decay?

• $y=5.2^x$

• $y=\left(\frac{5}{2}\right)^x$

• $y=0.52^x$

• $y=5\cdot2^x$

A radioactive substance decays at a rate of 6% per year. If the initial amount of the substance is 150 grams, which of the following functions models the remaining amount of the substance, in grams, after t years?

• $f\left(t\right)=150\left(1.06\right)^t$

• $f\left(t\right)=150\left(0.94\right)^t$

• $f\left(t\right)=150-150\left(1.06\right)^t$

• $f\left(t\right)=150-150\left(0.94\right)^t$

Tags

CCSS.HSF.LE.A.2

A colony of rabbits has a population of about 18,000 bunnies and is growing at a rate of about 1%. A colony of bees has a function describing its population as:   $b\left(t\right)=12000\left(1.02\right)^t$ . Which animal population has the higher growth rate?

• Rabbits
  

• Bees