Graphing a Function Rule

Continuous and Discrete Continuous data is data that is measured over time. (Time, weight, length, volume, etc.) You need an instrument to measure it… Discrete data is data that is counted. (Money, cars, etc.) When the word “each” is added to a measurement. The amount of time you spend washing dishes EACH day.

Continuous or Discrete Length of hair over a month Number of cars in the parking lot over a 24 hour period Student enrollment at Strack over 2 years Rainfall totals each month for the summer Number of desks in a classroom over the year Time you walk your dog each day for a week

Continuous or discrete? Example 1 Dependent variable (y) Independent variable (x) Scale You are paying to print pictures from your digital camera at the photo shop. You choose 4 x 6 pictures for all of them. These prints cost $0.49 each. Write a function rule for this. Make a table. Now graph it.

Graph the function rule: y = 3x - 2 Example 2 Graph the function rule: y = 3x - 2 Continuous or discrete? Dependent variable (y) Independent variable (x) Scale x y

Example 3 The cost C, in dollars for a health club membership depends on the number m of whole months you join. This situation is represented by the function rule C = 49 + 20m. What does the 49 represent? What does the 20 represent Continuous or discrete? Independent variable? Scale? Graph:

Example 4 Graph: y = |x| + 2

Example 5 Graph: y = x2 + 4

Example 6 The area, A, of a rectangle is a function of its width, w. If the length is always 5 cm in this case, write a function rule for this situation. Continuous or discrete? Independent variable? Dependent variable? Scale?

Example 7 What shape would the graph of y = x3 be? How can you find out? What about y = x4? What about y = x5? Do you see a pattern?