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Domains and Ranges of Functions

Answer Keys Here

Aligned To Common Core Standard:

High School Interpreting Functions - HSF-IF.A.2

What are the Domains and Ranges of Functions? Have you ever heard of domains and ranges of functions? You might have because mathematics is filled with such words. Much as these words are intimidating, they entail a lot of meaning to it. The domain of a function refers to the set of possible values of the independent variable. The domain is the set of all possible x-values, which will, when applied to the y-variable, will make the function work. When discovering the domain, bear in mind: The denominator (bottom) of a fraction shouldn't be zero. The number under the sign of square root must be positive in this section. The domain of a rational function consists of all the real numbers except the denominator. The range, on the other hand, is the complete set of all likely results of the dependent variable (y usually) after we have substituted the domain. The range is a set of values of the dependent variable that are a result of inserting the domain values into a function. To put it simply, the definition means: The resulting y-values you get after substituting the x-values in an equation.

Printable Worksheets And Lessons

Homework Sheets

We focus solely on range. This is because many teachers tell us that their is where the need is.

  • Homework 1 - The range of a function is the set of all possible y-values. The largest y-value on the graph appears at the vertex where y is mentioned by the formula.
  • Homework 2 - So, the range is the set of all real numbers. Let's see that on a graph and make sense of it.
  • Homework 3 - What is the range of this function? a {y | y ≤ 4}, b {y | y ≥ 4}, c {all real numbers}, d {y | y <4}

Practice Worksheets

You should see a brand new section on range to follow this shortly.

  • Practice 1 - This is one nice solid problem for you. A complete explanation is provided for you.
  • Practice 2 - When do you want to range this function out? This line jumps quadrants.
  • Practice 3 - You will need to count the lines here. This one is really large.

Math Skill Quizzes

Multiple choice is the common method used to assess this skill.

  • Quiz 1 - The domains is the set of all the inputs. We are focused on determining the possible outputs.
  • Quiz 2 - Some much larger values here. Use the values to get you going.
  • Quiz 3 - Scale this back to complete the values here.

How Does This Skill Apply to The Real World?

Functions are used to model mathematical systems that involve an input and an output. They are used in types of rule based mathematical patterns. If you go to any vending machine you would be using a rules based math system to make your purchase. Each coin you input results in validated outcome, once you put enough coins in to satisfy the output of the cost of the item that you choose, your purchase is complete. The bag of chips, bottle of water, of tasty treat will land to the bottom of the machine. Using our example of the vending machine we can see that the coins are the values that determine the domain. Assuming we the machine only accepts common coins, domain would be 1 (penny), 5 (nickel), 10 (dime), and 25 (quarter). The range is all the possible output values. In the sense of the vending machine the range would be the cost of all of the products that are available in the vending machine. You will find this skill to lend itself to just about any financial mathematical system like gas pumps and even street crossing signals. These measures are very helpful to understand the stress a system can contain and all of the possibilities that are available when you use it.