# Complex arithmetic resources

### Quick Reference (9)

Adding and Subtracting Complex Numbers

This leaflet explains how complex numbers can be added or subtracted.
There are accompanying videos. Sigma resource Unit 4.

Complex arithmetic

This leaflet explains how complex numbers can added, subtracted, multiplied and divided. (Engineering Maths First Aid Kit 7.2)

Division of complex numbers

This leaflet explains how to divide complex numbers. Sigma resource Unit 7.
There are accompanying videos.

Imaginary numbers and quadratic equations

This leaflet shows how the imaginary number i can be used in the solution of some quadratic equations. Sigma resource Unit 2.

Motivating the study of complex numbers

This unit introduces complex numbers by explaining how it is useful to be able to formally write down the square root of a negative number. Sigma resource Unit 1.

Multiplying complex numbers

This leaflet explains how complex numbers can be multiplied together.
There are accompanying videos. Sigma resource Unit 5.

The complex conjugate

This leaflet explains what is meant by the complex conjugate of a complex number.
There are accompanying videos. Sigma resource Unit 6.

What is a complex number

This leaflet explains what is meant by a complex number, and how to find its real and imaginary parts. Sigma resource Unit 3.

What is a complex number ?

This leaflet gives a simple, brief introduction to the concept of a complex number. (Engineering Maths First Aid Kit 7.1)