Equivalent expressions of functions
Equivalent recipes


This task presents computing recipes, where you strat out with an arbitrary number and follow the recipe to obtain a new number.

Choose any number and operate on it according to the three recipes. Try another number.
  • Explain what is meant by the fact that the three recipes are equivalent.
  • Construct correspondence rules to describe the three recipes. How can you prove that the three correspondence rules are equivalent?
  • Invent another recipe that is equivalent to the three recipes.
  • Invent a recipe that is not equivalent to the three given recipes. Invent other recipes that are equivalent to the recipe you invented.


  • Recipe 1
    a Choose any number:
    b Add 1 to the number in line a and multiply the result by 2:
    c Add 1 to the number in line b and multiply the result by 2:
    d Add 1 to the number in line c and multiply the result by 2:


    Recipe 2
    a Choose any number:
    b Multiply the number in line a by 2:
    c Add 3 to the number in line b:
    d Multiply the number in line c by 4:
    e Add 2 to the number in line d:


    Recipe 3
    a Choose any number:
    b Add 2 to the number in line a:
    c Multiply the number in line b by 8:
    d Subtract 2 from the number in line c:






    The form f(x)=ax+b
    The form f(x)=a(x-c)
    The form
    f(x)=a(x-c)+m

    Emphasizing information
    Emphasizing intersections
    Families of functions
    Features from value tables
    Partial pictures
    Equivalent recipes
    Telephone rates
    Verbal descriptions of equivalent expressions
    Stories
    Describing a trip
    Speeding car

    Exercise 1
    Exercise 2
    Exercise 3
    Exercise 4
    Exercise 5
    Exercise 6
    Exercise 7
    Exercise 8
    Exercise 9
    Exercise 10
    Exercise 11
    Exercise 12
    Exercise 13
    Exercise 14
    Exercise 15
    Exercise 16
    Exercise 17
    Exercise 18
    Exercise 19