1. Warm-up 7-7

2. Lesson 7-7: Imaginary & Complex Numbers
Objectives:
Students will:
Express the square root of negative numbers and their products in terms of I
Add or subtract complex numbers

3. Imaginary Numbers
Used to solve the square roots of negatives
i is the imaginary unit where i2 = -1
Since i2 = -1, then
Find a pattern
i1 =
i2 =
i3 =
i4 =
i5 =
i6 =
Pattern:

4. Numbers with a real and imaginary parts
Example 1 Example 2 Example 3
If there is a negative under a square (even) root you must factor a “-1”
Complex Numbers
Numbers with a real and imaginary parts
a + bi ; a and b are real numbers
You can add and subtract like parts

5. Example 4 Example 5
(2i + 1) + (5i + 3) (-4i – 3) – (2i + 5)
HW 84