Exponential Functions Standard: A.CED.1

Essential Questions: How do I make a table of values for an exponential function? How do I graph an exponential function?

Steps: Make a table of values by plugging in x-values (domain) into the function and getting y- values (range). You now have ordered pairs. Plot your new ordered pairs on a coordinate plane. Draw the curve.

Example 1 Graph y = 3 x by making a table of values. Use 0, 1, and 2 as your domain.

Example 2 Graph y = ⅟ 2 x by making a table of values. Use 0, 1, and 2 as your domain.

Example 3 Graph y = 2 x by making a table of values. Use 0, 1, and 2 as your domain.

Exponential Growth and Decay: a = initial amount before measuring growth/decay r = growth/decay rate (often a percent) x = number of time intervals that have passed

Steps: Read the word problem and identify “a”, “r”, and “x”. Choose whether the problem is a growth or decay problem – (look for words like increase and decrease). Plug values into appropriate formula and solve.

Example 4 A new TV costs $1200. The value of the TV decreases by 21% each year. Write a model giving the TV’s value after 2 years. a = 1200 r = 21% x = 2 Growth or Decay? Decay 1200(1-.21) 2 $748.92

Example 5 Glynn County’s population in 2010 was 70,000. Each year the population increases by 5%. Write a model giving the county’s population in a = 70,000 r = 5% x = 5 Growth or Decay? Growth 70,000(1+.05) 5 89,339

Summarizer: How do I graph an exponential function? Make a table of values

Assignment: worksheet