To divide two complex numbers, multiply by the complex conjugate of the denominator.

## Summary/Background

A
note about graphic calculatorsA graphic calculator, for example the TI-83 or similar model, can work with complex numbers. First select MODE and move down to select a+bi:Then press 2nd QUIT and enter a complex number sum. |

## Software/Applets used on this page

## Glossary

### complex number

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

### conjugate

of a complex number a+bi is a-bi.

### denominator

the integer on the bottom of a fraction

### mode

the value in a set of discrete data that occurs most frequently

### union

The union of two sets A and B is the set containing all the elements of A and B.

### work

Equal to F x s, where F is the force in Newtons and s is the distance travelled and is measured in Joules.

## This question appears in the following syllabi:

Syllabus | Module | Section | Topic |
---|---|---|---|

AQA A-Level (UK - Pre-2017) | FP2 | Complex Numbers | Complex algebra |

AQA AS Further Maths 2017 | Pure Maths | Complex Number Basics | Complex Algebra |

AQA AS/A2 Further Maths 2017 | Pure Maths | Complex Number Basics | Complex Algebra |

Core Pure | Complex Numbers | Complex Algebra | |

CBSE XI (India) | Algebra | Complex Numbers and Quadratic Equations | Imaginary unit |

CCEA A-Level (NI) | FP1 | Complex Numbers | Complex algebra |

CIE A-Level (UK) | P3 | Complex Numbers | Complex algebra |

Edexcel A-Level (UK - Pre-2017) | FP1 | Complex Numbers | Complex algebra |

Edexcel AS Further Maths 2017 | Core Pure Maths | Complex Numbers | Complex Algebra |

Edexcel AS/A2 Further Maths 2017 | Core Pure Maths | Complex Numbers | Complex Algebra |

I.B. Higher Level | 1 | Complex Numbers | Complex algebra |

Methods (UK) | M3 | Complex Numbers | Complex algebra |

OCR A-Level (UK - Pre-2017) | FP1 | Complex Numbers | Complex algebra |

OCR AS Further Maths 2017 | Pure Core | Complex Number Basics | Complex Algebra |

OCR MEI AS Further Maths 2017 | Core Pure A | Complex Number Basics | Complex Algebra |

OCR-MEI A-Level (UK - Pre-2017) | FP1 | Complex Numbers | Complex algebra |

Pre-U A-Level (UK) | 7 | Complex Numbers | Complex algebra |

Scottish Advanced Highers | M2 | Complex Numbers | Complex algebra |

Scottish (Highers + Advanced) | AM2 | Complex Numbers | Complex algebra |

Universal (all site questions) | C | Complex Numbers | Complex algebra |

WJEC A-Level (Wales) | FP1 | Complex Numbers | Complex algebra |