1. 5.4 Complex Numbers

2. Let’s see… Can you find the square root of a number? A. E.D. C.B.

3. So What’s new? To find the square root of negative numbers you need to use imaginary numbers. i is the imaginary unit i 2 = -1 i = Square Root Property For any real number x, if x 2 = n, then x = ±

4. What about the square root of a negative number? E.D. C. B. A.

5. Let’s Practice With i Simplify -2i (7i) (2 – 2i) + (3 + 5i) i 45 i 31 A. B. C. D. E.

6. Solve 3x 2 + 48 = 0 4x 2 + 100 = 0 x 2 + 4= 0 A. B. C.

7. 5.4 Day #2 More with Complex Numbers Multiply (3 + 4i) (3 – 4i) (1 – 4i) (2 + i) (1 + 3i) (7 – 5i) (2 + 6i) (5 – 3i)

8. *Reminder: You can’t have i in the denominator Divide 3i5 + i 2 + 4i 2i -2i4 - i 3 + 5i 5i 2 + i 1 - i E. D. C. B. A.