1. Chapter 2 Section 4
Complex Numbers

2. Imaginary Numbers
Imaginary Unit: the unit i can be used to write the square root of any negative number.
Pattern?

3. Try these
1.) i27 2.) i54 3.) i65 4.) i60

4. Complex Numbers
A complex number written in standard form is a number a+bi. where a and b are real numbers.
If b does not equal zero, then a+bi is an imaginary number.
If a=0 and b does not equal zero, then a+bi is a pure imaginary number

5. Properties of Square Roots of Negatives
If r is a positive real number, then :
Example:
Extra Examples:

6. Examples:
1. Solve

7. Adding and Subtracting Complex Numbers

8. Examples: 1. 2.

9. Multiplying and Dividing Complex Numbers
Multiplying: Use same properties you would when multiplying real numbers
Dividing: Multiply fraction by complex conjugate (the opposite of what the denominator is)

10. Examples 1. 2.

11. Examples
3.)
4.)

12. Homework
Page 167# 17-22, 27-30, 46-49