Evaluating a Function

Let's start with a test!

The Test

Here is a -question, multi-choice test for the "Evaluating a Function" lesson. The pass mark is 90%. Don't worry! All the information you need to pass is in the lesson section under the test.

The Lesson

A function is a relation between a set of inputs and a set of outputs, such that each input is related to exactly one output. Evaluating a function means putting an input into a function, and finding the output it relates to.

Understanding Evaluating a Function

To evaluate a function means to see what output an input is mapped to. The image below shows a mapping diagram which relates a set of inputs to a set of outputs. If we wanted to evaluate the function when the input is 2, we would see which output it is mapped to. Imagine we have the function below:If we evaluate the function at x = 2, we need to find f(2).

A Real Example of How to Evaluate a Function

Evaluating a function is easy.

Step-by-Step:

Answer:

If we evaluate f(x) = 2x + 1 at x = 2, we get 5. f(2) = 5.

A Note on Notation

If a function f is evaluated at a number (e.g. 2), this is denoted f(2).

You might also like...