PSAT Math

A comprehensive guide to mastering the math concepts tested on the PSAT, including real-world applications and testing strategies.

Advanced Topics

Functions and Their Properties

What Is a Function?

A function is like a machine: you put in a number (input), and it gives you a result (output) following a specific rule.

Identifying Functions

Each input has exactly one output. You might see functions represented as equations, tables, or graphs.

Key Properties

Learn about domain (all possible inputs) and range (all possible outputs). Recognizing these helps you interpret graphs and solve real-world problems.

PSAT Focus

The PSAT may ask you to evaluate functions or interpret function notation, like \(f(x)\).

Key Formula

\[f(x) = 2x + 5\]

Examples

  • If \(f(x) = 2x + 5\), then \(f(3) = 2 \times 3 + 5 = 11\).

  • A vending machine that gives you a snack for every dollar is like a function: each dollar (input) gives one snack (output).

In a Nutshell

Functions connect inputs to outputs—a foundational concept for higher math.

Key Terms

Domain
All possible input values for a function.
Range
All possible output values for a function.
Function Notation
A way to name functions, like \(f(x)\).
Functions and Their Properties - PSAT Math Content | Practice Hub