Mastering Functions: Understanding f(x) Notation and Input Values

Mastering Functions: Understanding f(x) Notation and Input Values

Learning Objective

At the end of the lesson you will understand the f(x) notation, and be able to input different values into a given function.

What do you already know about functions in algebra?

Understanding f(x) Notation

f(x) notation represents a function where 'x' is the input. The function f(x) tells us what to do with the input 'x' to get the output.

Inputting Values into a Function

To input a value into a function, substitute the value for 'x' in the function expression. The result is the output corresponding to that input.

Example 1: Inputting Values

Given the function f(x) = 2x + 3, let's input x = 4. f(4) = 2(4) + 3 = 11. So, when x = 4, f(x) = 11.

Example 2: Inputting Values

Now, let's input x = -2 into the function f(x) = x^2 - 5. f(-2) = (-2)^2 - 5 = 4 - 5 = -1. So, when x = -2, f(x) = -1.

Interactive Exercise

Students will be given simple functions and asked to input different values to calculate the corresponding outputs.

Real-Life Application

Functions are used in various real-life scenarios such as calculating costs, predicting outcomes, and analyzing trends.

Summary and Recap

Today we learned about the f(x) notation, how to input values into a function, and saw examples of how functions work in algebra.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.