MathematicsChapter 6: Functions and Graphs
Function Or Not
Each first component appears once.
Learning objectives
- Define and explain function or not.
- Apply function or not to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Definition
Each first component appears once. R2 = {(2,3),(6,1),(8,3),(6,5)} is not a function because 6 maps to 1 and to 5. Repeating an output is allowed; repeating an input with two outputs is not.
Formula
R2 =
Where / symbols
- Function Or Not
- Each first component appears once. R2 = {(2,3),(6,1),(8,3),(6,5)} is not a function because 6 maps to 1 and to 5. Repeating an output is allowed; repeating an input with two outputs is not.
Relationship
- domain = inputs
Overview
Learn the idea, then use it:
Core Understanding
Each first component appears once. R2 = {(2,3),(6,1),(8,3),(6,5)} is not a function because 6 maps to 1 and to 5. Repeating an output is allowed; repeating an input with two outputs is not.
Examples input unique · one output per input · domain = inputs · FUNCTION OR NOT: Each first component appears once. R2 = {(2,3),(6,1),(8,3),(6,5)} is not a function because 6 maps to 1 and to 5. Repeat
Exam Application
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Examples Define first · Show the rule or evidence · Check units, labels, and conclusion
WHAT — FUNCTION OR NOT
Each first component appears once. R2 = {(2,3),(6,1),(8,3),(6,5)} is not a function because 6 maps to 1 and to 5. Repeating an output is allowed; repeating an input with two outputs is not.
HOW — Use the idea
Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check the result.
In simple words
Do not merge function or not with a neighbouring idea that uses a different definition, rule, or method.
Key points
- input unique
- one output per input
- domain = inputs
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Function Or Not
Sticky Notes · Quick Revision
Core Idea
- Each first component appears once.
Key Points
- input unique
- one output per input
- domain = inputs
Simple Check
- Explain function or not in your own words and connect it to one chapter example.
How to Answer
- Define the idea, show the main rule or evidence, apply it, and check the final statement.
Common Mistake
- Do not merge function or not with a neighbouring idea that uses a different definition, rule, or method.
FBISE Exam Tip
- Use the exact term, show working where needed, and include units or labelled evidence.
60-second revision
- Each first component appears once.
- input unique
- one output per input
- domain = inputs
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