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This Argand diagram shows how complex numbers a and b are subtracted to produce the complex number c. This addition is similar to the "parallelogram law" for adding vectors.
the Argand diagram illustrates a - b = c
if a = c + di and b = e + fi, then c = a - b = (c-e) + (d-f)i
|a - b| is not equal to |a| - |b|
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Software/Applets used on this page

Cinderella
Uses Cinderella interactive geometry

Glossary

argand diagram

A geometrical presentation of a complex number; using a real and imaginary axis to plot a+ib as (a,b).

complex number

A number of the form a+bi where i is the square root of -1, and a and b are real.

Full Glossary List

This question appears in the following syllabi:

SyllabusModuleSectionTopicExam Year
AQA A-Level (UK - Pre-2017)FP2Complex NumbersArgand diagram-
AQA AS Further Maths 2017Pure MathsComplex Number BasicsArgand Diagrams-
AQA AS/A2 Further Maths 2017Pure MathsComplex Number BasicsArgand Diagrams-
CBSE XI (India)AlgebraComplex Numbers and Quadratic EquationsArgand diagrams-
CCEA A-Level (NI)FP1Complex NumbersArgand diagram-
CIE A-Level (UK)P3Complex NumbersArgand diagram-
Edexcel A-Level (UK - Pre-2017)FP1Complex NumbersArgand diagram-
Edexcel AS Further Maths 2017Core Pure MathsArgand DiagramsArgand Diagrams-
Edexcel AS/A2 Further Maths 2017Core Pure MathsArgand DiagramsArgand Diagrams-
I.B. Higher Level1Complex NumbersArgand diagram-
Methods (UK)M3Complex NumbersArgand diagram-
OCR A-Level (UK - Pre-2017)FP1Complex NumbersArgand diagram-
OCR AS Further Maths 2017Pure CoreArgand Diagrams and LociArgand Diagrams-
OCR MEI AS Further Maths 2017Core Pure AArgand Diagrams and LociArgand Diagrams-
OCR-MEI A-Level (UK - Pre-2017)FP1Complex NumbersArgand diagram-
Pre-U A-Level (UK)7Complex NumbersArgand diagram-
Scottish Advanced HighersM2Complex NumbersArgand diagram-
Scottish (Highers + Advanced)AM2Complex NumbersArgand diagram-
Universal (all site questions)CComplex NumbersArgand diagram-
WJEC A-Level (Wales)FP1Complex NumbersArgand diagram-