1. 2.4 Complex Numbers Standard form of a complex number a + bi Adding and Subtracting complex numbers (3 – i) + (2 + 3i) = 2i + (-4 – 2i) = 3 - (-2 + 3i) + (-5 + i) = 5 + 2i -4 -2i

2. Multiplying Complex numbersNote: i 2 = -1 (i)(-3i) = (2 – i)(4 + 3i) = (3 + 2i)(3 – 2i) = -3i 2 =3 8 + 6i – 4i – 3i 2 = 11 + 2i 9 – 4i 2 = 9 + 4 = 13 Dividing Complex numbers -6

3. Note: -6 -3

4. Use the quadratic formula to solve 0 = 3x 2 – 2x + 5

5. i 1 = i i 2 = -1 i 3 = -i i 4 = (i 2 ) 2 =(-1) 2 = 1 i 5 = i What does i 36 =(i 2 ) 18 =(-1) 18 =1 i 53 = i