Activities to Teach Students the Composition of Linear and Quadratic Functions: Find a Value

As any math teacher knows, teaching students about functions can be a challenging task. Especially when it comes to the composition of linear and quadratic functions – this requires a solid understanding of the basics of algebra and some specific skills. However, there are several activities that can make this process more interesting and effective. One particularly useful tool for teaching the concept of function composition is finding the value of a function given an input.
Here are three possible activities to help teach students about function composition and finding the value of a function:
1. The Function Machine
The function machine is a classic teaching tool used to show how input values are transformed by a function. To create a function machine, you’ll need some sort of container (a box, a jar, etc.) and a set of labeled disks or cards with numbers or expressions on them. Students should take turns drawing a card from the container, and then feed the card into the function machine. The teacher can then apply the function to the input value and announce the output. For example, if the card drawn is “x+3” and the function is f(x) = 2x, the output would be f(x+3) = 2(x+3) = 2x+6.
This activity can be adapted to linear and quadratic functions by using different functions and input values for each round. When students are comfortable with the concept of function composition, they can take turns acting as the “function machine” themselves.
2. Plug and Chug
This activity is fairly straightforward – students are given a function and an input value and are asked to calculate the output. The teacher can provide a set of problems that gradually increase in difficulty, starting with basic linear functions such as f(x) = 3x+2 and progressing to more complex quadratic functions like f(x) = x^2-4x+7.
To make this activity more engaging, try using a game show format where students compete to see who can solve the problem correctly first. This activity is a great way to reinforce the idea of function composition and help students practice basic algebraic manipulations.
3. Function Composition Relay
In this activity, the class is divided into teams of three or four students. Each team is given a set of functions and an input value, and each member of the team is responsible for solving one part of the problem. For example, the first team member might need to calculate g(x) given an input value of x, the second member would then need to calculate f(g(x)), and the third member would need to calculate h(f(g(x))). Once each team has calculated the final output value, they race to be the first to announce the correct solution.
This activity is a fun way for students to work together and practice function composition while building teamwork skills.
In conclusion, teaching the composition of linear and quadratic functions can be challenging, but it doesn’t have to be boring. Activities that center around finding the value of a function given an input are a great way to make the concept more engaging and approachable for students. These activities can be adapted to suit a range of skill levels and learning styles, and can help students build the foundation they need for future math studies.