Topic explanation

Standard explanation

f(x)=sqrt(x) has domain x>=0 and range y>=0. f(x)=1x has domain x!=0. f(x)=|x| has range y>=0. Read restrictions from the formula before evaluating.

Key points

• where it is defined
• one output per input
• domain = inputs
• keep the ideas separate
• Domain And Range: f(x)=sqrt(x) has domain x>=0 and range y>=0. f(x)=1x has domain x!=0. f(x)=|x| has range y>=0. Read
• WHAT — DOMAIN AND RANGE: f(x)=sqrt(x) has domain x>=0 and range y>=0. f(x)=1x has domain x!=0. f(x)=|x| has range y>=0. Read
• HOW — Use the idea: Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check
• CORE UNDERSTANDING: f(x)=sqrt(x) has domain x>=0 and range y>=0. f(x)=1x has domain x!=0. f(x)=|x| has range y>=0. Read

Labelled diagram