1. 5.6 Complex Numbers

2. Complex number: a + bi where a is the real number part and bi is the imaginary number part

3. imaginary number (i)

4. Ex 1

5. Ex 2
Write in a + bi form

6. Ex 3
Find the additive inverse of -7 – 9i

7. Ex 4
(6 – 2i) + (-5 + i) (3 + 6i) – (4 – 8i)

8. Ex 5
(3i)(8i) (3i)(-5 + 2i) (4 + 3i)(-1 – 2i)

9. MEMORIZE!!!!!!!!!!

10. Simplify
i47

11. Solve: 9x2 + 54 = 0 Factor: x2 + 81 Factor: 2x2 + 32

12. (a + bi) and (a – bi) are called complex conjugates
The product of complex conjugates is a REAL number.
(2 + 3i)(2 – 3i)
Why can you not have ‘i’ in the denominator of a fraction?

13. Simplify:

15. Think:
Explain the difference between the additive inverse of a complex number and a complex conjugate.