This document discusses multiplying complex numbers. It explains using the distributive property or foil method to multiply complex numbers. It also discusses getting rid of complex numbers in the denominator by multiplying by the complex conjugate. The document provides examples of multiplying complex numbers and writing the expression in standard complex number form.

1. 5.7 day 2.notebook November 30, 2012
Multiplying complex numbers
use the distributive property or the foil method
2i(­1 + 3i) (6 + 3i)(4 ­ 3i)
1

2. 5.7 day 2.notebook November 30, 2012
Must get rid of complex number in the denominator.
So to do this we multiply by the complex conjugate.
3 + 2i
1 ­ 2i
2

3. 5.7 day 2.notebook November 30, 2012
­5
i
3

4. 5.7 day 2.notebook November 30, 2012
Extra if needed.
Write the expression as a complex number in standard form.
3i(2 ­ i) (1 + 2i)(2 ­ i) 2 + i
1 ­ i
4